Removed unused methods.
Removed unused methods.

mikz/slack-ruby-client,slack-ruby/slack-ruby-client,mikz/slack-ruby-client,dblock/slack-ruby-client,rkadyb/slack-ruby-client,jlyonsmith/slack-ruby-client,slack-ruby/slack-ruby-client,jlyonsmith/slack-ruby-client,dblock/slack-ruby-client,rkadyb/slack-ruby-client