[ZabbixAPI] Fix a typo in a comment
falgs ->
flags
[ZabbixAPI] Drop "value_flags" in trigger object against Zabbix 2.2

Because it's a deprecated value on Zabbix 2.2.
github issue #221
[ZabbixAPI] Modify the comment about value_flags of trigger object
[testArmZabbixAPI] Add tests for getting triggers against Zabbix-2.2.0 & 2.2.2
Merge pull request #223 from project-hatohol/zabbix-2.2.0

[Issue #221] Fix a bug that can't get triggers from Zabbix 2.2.0 - 2.2.1