[feature]create comments model

Note: this comment model will be the relation model between users and
images, to get comment-related things
[feature]relation between users and images for the comments
[feature]create controller for comments

Note: add test/support/ just like Rspec, to add a new MatchArray to the
minitest's Assertions
[chore]remove default tests for images_controller to make tests pass
Merge pull request #5 from peterzd/comments

Comments