Squashed

[#53] Correct misspell valid to invalid

[#51] Add create event with unit test
- Add more test DateTime in create_event_spec.rb
- Add in Gemfile gem geodecoder
- Correct in model error from flash to http
- Correct format in calendar.rb for create!
[#53] Correct error message
[#53] Add create event with unit test
- Remove gem geocoder from Gemfile non needed in API
- Remove geocoder walidation in model non needed in Api
- Remove DateTime parse in model non needed when use Datepicker
- Add raise_errors
Another squashed
[#53] [API] Add create event with unit test
- Modified error message in model from event
- add rescue in calendar.rb
- add test in create_event to check is message right
[#53] Add create event with unit test
- add context
[#53] add test for response is Json
[#53] add more context and add more clearly error
[#53] Add more specific error and add subject to test
[#53] [API] Add create event with unit test
- add more message test
- add expect block
[#59] Add index action for user.
Third Squash
[#59] Add test for no users in database; clean-up.]
[#59] Update Readme for User#index.
Forth squashed
Fifth squashed
Sixth squashed
[#62] Add show action for user, update Readme.
Seventh squashed
Eighth squashed