Tests: add ruby style and code checks via rubocop

At the moment all plugins fail the test out of various reasons.
Thus they are exempted from causing test failures.

But future (new) plugins will fail the test and thus indicate the
relevant steps to fix issues before a plugin is included.

.travis.yml

@@ -16,6 +16,7 @@ addons:
       - zsh
       - pylint
       - shellcheck
+      - rubocop
       - pkg-config
       - libdb-dev
       - libvirt-dev

t/test-exception-wrapper.expected-failures

@@ -30,6 +30,7 @@ plugins/bind/bind9_socket_stats
 plugins/bsd/df_abs_bsd
 plugins/bsd/df_bsd
 plugins/bsd/freebsd_hdd_power_state
+plugins/bsd/netstat_bsd_m_
 plugins/bsd/spamd-blacklist-bsd
 plugins/bsd/spamd-tarpit-bsd
 plugins/cacti/cacti-host
@@ -90,6 +91,7 @@ plugins/dspam/dspam_activity
 plugins/dvb/2wcomdsr_
 plugins/dvb/femon
 plugins/ejabberd/ejabberd_resources_
+plugins/ejabberd/ejabberd_scanlog
 plugins/emc/emc_vnx_block_lun_perfdata
 plugins/emc/emc_vnx_file_
 plugins/fan/dell_fans
@@ -148,11 +150,14 @@ plugins/harddisks/powered_up_
 plugins/horde/horde
 plugins/http/http_pagespeed
 plugins/http/http_responsecode
+plugins/http/mongrel_memory
+plugins/http/mongrel_process_memory
 plugins/http/vhost_requests_
 plugins/http/wget_page
 plugins/i2p/i2p_
 plugins/icecast/icecast_
 plugins/icecast/icecast2
+plugins/icecast/icecast2_simple
 plugins/icecast/icecast2_stats_
 plugins/imapproxy/imapproxy_multi
 plugins/ip6/ip6_
@@ -187,7 +192,9 @@ plugins/memory/kmemsum
 plugins/memory/multimemory
 plugins/memory/proc_mem
 plugins/memory/proc_memory_status
+plugins/minecraft/minecraft-users
 plugins/mixminion/mixminion
+plugins/moblock/moblock_connections
 plugins/mod_jk/mod_jk
 plugins/moinmoin/moinoin_pages
 plugins/mongodb/mongo_btree
@@ -197,6 +204,10 @@ plugins/mongodb/mongo_lag
 plugins/mongodb/mongo_lock
 plugins/mongodb/mongo_mem
 plugins/mongodb/mongo_ops
+plugins/mssql/microsoft-sql
+plugins/mssql/microsoft-sql-buffer-cache-hit-ratio
+plugins/mssql/microsoft-sql-data-file-sizes
+plugins/mssql/microsoft-sql-log-file-size
 plugins/mumble/mumble_users
 plugins/mumble/murmur-stats
 plugins/munin/healthcheck_log
@@ -220,6 +231,7 @@ plugins/network/fwbuilder_
 plugins/network/hfsc
 plugins/network/hfsc_sep
 plugins/network/host_traffic
+plugins/network/http__tp_link
 plugins/network/if1sec_
 plugins/network/ifem_
 plugins/network/if_uptime
@@ -235,6 +247,7 @@ plugins/network/mtr100_
 plugins/network/netatalk
 plugins/network/netatalk3
 plugins/network/net_hosts_
+plugins/network/netstat_s_
 plugins/network/nsd3
 plugins/network/olsrd
 plugins/network/packetloss
@@ -270,20 +283,27 @@ plugins/ntp/ntp_pool_score_
 plugins/openntpd/openntp_offset
 plugins/openvz/openvz_
 plugins/oracle/oracle_connections
+plugins/oracle/oracle-pga-monitor
+plugins/oracle/oracle-sga
 plugins/oracle/oracle_sysstat
 plugins/ossec/ossec_active_response
 plugins/ossec/ossec_agents
 plugins/ossec/ossec_alerts
 plugins/other/beanstalkd
 plugins/other/cm2
+plugins/other/delayed_jobs_queue_size
 plugins/other/earthquakes-stronger-than-m4-and-m5-plus-solar-act
 plugins/other/foldingathome_activecpu
 plugins/other/globesurfer
 plugins/other/hookbox
 plugins/other/listeners
 plugins/other/pid
+plugins/other/port_
 plugins/other/s9y
 plugins/other/services
+plugins/passenger/passenger_memory
+plugins/passenger/passenger_processes
+plugins/passenger/passenger_status
 plugins/pdns/pdns_errors
 plugins/pdns/pdns_queries
 plugins/pdns/pdns_rec_qtypes
@@ -298,6 +318,7 @@ plugins/php/eaccelerator-python
 plugins/php/php5-fpm_status
 plugins/php/php_apc_
 plugins/php/php-cgi
+plugins/php/php_eaccelerator
 plugins/php/php_errors_
 plugins/php/php_opcache
 plugins/php/php_sessions
@@ -354,6 +375,7 @@ plugins/printer/toshiba_5520c_scan_
 plugins/printer/xerox-wc3220
 plugins/printer/xerox-wc7232-consumables
 plugins/puma/puma_
+plugins/puppet/puppet_runtime
 plugins/qmail/qmailconn
 plugins/qmail/queuestats
 plugins/qmail/spamdyke
@@ -373,17 +395,20 @@ plugins/rethinkdb/rethinkdb_node_io
 plugins/riak/riak_fsm_time_95
 plugins/riak/riak_memory
 plugins/riak/riak_node
+plugins/router/ag241-adsl
 plugins/router/arris-tm502g_
 plugins/router/bbox
 plugins/router/cisco-epc3010_
 plugins/router/conexant_adsl
 plugins/router/dartybox
+plugins/router/d-link-dir-655-router-statistics-plugin
 plugins/router/dsl-connection-speed
 plugins/router/dsl-stats
 plugins/router/freeboxuptime
 plugins/router/motorola_sb6141
 plugins/router/snmp__juniper
 plugins/router/snmp__juniper_spu
+plugins/router/snmp__linksys_poe
 plugins/router/speedport_300
 plugins/rsync/rsyncd_bytes
 plugins/rsync/rsyncd_count
@@ -405,6 +430,7 @@ plugins/smstools/smstools_
 plugins/snmp/snmp___bri_se_
 plugins/snmp/snmp__brocade_ifs
 plugins/snmp/snmp__fn
+plugins/snmp/snmp_room_alert_
 plugins/snmp/snmp__webthermometer
 plugins/solaris/io_disk
 plugins/solaris/zones_cpu
@@ -414,6 +440,7 @@ plugins/sphinx/sphinx_documents
 plugins/squid/squid_efficiency
 plugins/squid/squid_times
 plugins/ssh/openssh-denyhosts
+plugins/ssh/sshd_invalid_countries_ruby
 plugins/ssh/sshd_log
 plugins/streaming/packetship_
 plugins/swift/swift-async_
@@ -426,6 +453,9 @@ plugins/system/file_length_
 plugins/tarsnap/tarsnap
 plugins/tcp/tcp-retransmissions
 plugins/tcp/tcp-states
+plugins/thin/thin_memory
+plugins/thin/thins_peak_memory
+plugins/thin/thin_threads
 plugins/tinydns/tinydns
 plugins/tinydns/tinydns_err
 plugins/tor/tor_traffic
@@ -433,6 +463,8 @@ plugins/trafic_ro/trafic_ro_24h
 plugins/tv/hdhomerun_
 plugins/twemproxy/nutcracker_requests_
 plugins/unicorn/unicorn_
+plugins/unicorn/unicorn_memory_status
+plugins/unicorn/unicorn_status
 plugins/user/membyuser
 plugins/user/multipsu
 plugins/user/system_users
@@ -442,6 +474,7 @@ plugins/vmware/esxcli_env_
 plugins/vmware/esxi
 plugins/vmware/esxi__sensors
 plugins/vmware/vm_cpu_load
+plugins/voldemort/voldemort
 plugins/vpn/openvpn_as_mtime
 plugins/vpn/openvpn_as_traffic
 plugins/vpn/openvpn_as_ttime

t/test.t

@@ -192,12 +192,21 @@ sub process_file {
         );
     }
     elsif ( $interpreter =~ m{j?ruby} ) {
-        run_check(
-            {   command     => [ 'ruby', '-cw', $file ],
-                description => 'ruby syntax check',
-                filename    => $filename
-            }
-        );
+        subtest $filename => sub {
+            plan tests => 2;
+            run_check(
+                {   command     => [ 'ruby', '-cw', $file ],
+                    description => 'ruby syntax check',
+                    filename    => $filename
+                }
+            );
+            run_check(
+                {   command     => [ 'rubocop', $file ],
+                    description => 'ruby style and syntax check',
+                    filename    => $filename
+                }
+            );
+        }
     }
     elsif ( $interpreter =~ m{gawk} ) {
         run_check(