Remove unused methods related to authors

A few of these methods were being used but after inspecting production 
there were no values other than nil being returned.
Fix the build :(

* Remove BlogApp::Author and depend on Person instead
* Move truncate_html dependency out of main app into engine
* Update engine migrations to have columns that production has
* Remove specs of questionable value
Run blog engine specs as part of ci
Merge branch 'fix-broken-blog-engine-specs'

* fix-broken-blog-engine-specs:
  Run blog engine specs as part of ci
  Fix the build :(
  Remove unused methods related to authors