1. Resource state events api's added
2. Linking resoruce state event module into client.rb

Resource state event api added in Gitlab 3.2

1. Space after comma fixed
2. Frozen string literal added to top of file

Space after comma fixed in one more occurance

1. Resource state event/events for issue
2. Resource state event/events for MRs

Tests for
1. Issue resoruce state events/event
2. MR resource state event/events

Shell completion returned newly added issue state events.
Modified the test to accomodate the newly added issue state events.