Lesson plan index table sort

- Added sorting by columns
- Added image next to column name to indicate sort direction
updated spec to use specific date rather than DateTime.now
Add search functionality for lesson plans and wrote model, controller, and feature specs
Add missing file
Search handles nil case

Remove search template and render index instead
testing travis-ci
added poltergeist to use phantomjs for js tests
added heroku deploy to travis config
added bundler args for travis
added bundler args for travis and update gemfile
Travis ci
- added heroku as provider
- added bundler args
- update gemfile
Merge branch 'search' of https://github.com/luketower/yo_teach into luketower-search

Conflicts:
  app/models/lesson_plan.rb
  spec/features/lesson_plans_spec.rb
moved sqlite gem back to test
Merge branch 'master' into luketower-search
fixed failing specs
updated simple cov init
update app name for travis deploy
Fix search to eliminate case dependence