Re-added observers

Also added a very simple index.html.erb that replaces the dynamically
loaded js.erb-file, just to show what goes into ChooChoo::Carriage.
A first example of Concerns
Merged master fixed conflict
Fix db in travis tests
Fix merging conflicts
Removed observer initialization
Trying without the before-script...
Merge branch 'concerns' of github.com:lnucrowding/choo_choo into concerns
Hopefully fixed travis runs
Removed Locomotive-model (observer)
Extended (+ renamed) concerns
Extended Carriage model with more fields and validation

Includes migration file for Carriage
Added tests - simple factory for carriage + rspec test
Updated schema for dummy app
Added default styling to display notifications
Updated readme with new installation instructions
Updated spec to new syntax and disabled the old one
Update index.js.erb
Some very simple tests for Carriage
Adding skeleton of concerns test