Comprehensive unit tests for Comment. Some issues outstanding.
Merge branch 'master' into Comment_Unit_Tests
Added proper presence validators for :user and :gadget.
Removed unnecessary associations validator. Added validations to Vote.
Merge branch 'master' into Comment_Unit_Tests
Added more unit tests for Vote.
Merge branch 'master' into Comment_Unit_Tests
Finished unit tests for Vote.
Merge pull request #5 from AlecHFerguson/Comment_Unit_Tests

Model unit tests