RubyGems: Remove "ruby", "gem", and "gems" triggers.

These are ambiguous triggers.
RubyGems: Remove "ruby xml" test.

"ruby" is a very ambiguous and should not refer to RubyGems.
RubyGems: Get the original query and add a maximum to the list.
RubyGems: Add more trigger words.
RubyGems: Add "gem install" as a trigger.
RubyGems: Add the trigger word 'gem'.
Merge pull request #424 from duckduckgo/jag/release/rubygems

Release: RubyGems