Updated for simplecov
Moved comments for posts from its own directory comments to
the posts directory in preparation for project comments.
Created some tests for adding comments to projects.
Added commentable_id and commentable_type to the comments table for
polymorphic comments.  Also removed post_id, since it is no longer
needed.
Replaced posts and added commentable and polymorpic attributes
so make the comment model usable by posts and projects.
Added a many comments to one post or project association with
commentable.
Changed routes for posts and projects to be nested to support
having many comments.
Fix spelling error.
Restructured the nested resources. Original implementation following
the railscast sent me in the wrong direction.
Moved the navigation bar to the application layout so that all
forms can utilize it without have navigation bars in every form.
Renamed heading to be consistent with other forms.
Updated the contents of the yml file to reflect commentable and
commentable_type.
Updated create method for commentable.
Update the feature test to include adding comments to projects.
Fixed a spelling mistake.  Changed polymorpic to polymorphic.
Replace post with commentable so that I can take advantage of the
polymorphic features.
Removed form specific navigation bar so that I can use the shared one
in the application layout.
Replaced the symbol names of the test data to support utilizing
the polymorphic features.
Added a resource for comments since it is now polymorphic.
Cleaned up some to of the methods.