Implemented Pingr with Specs

Closes #21
Removed migration files from dummy app too - Fixes #22
Merge branch 'feature/SearchEnginePing'
Updated README about Pingr
Releasing v0.7.0
Added a Gem Version badge to README.md
Added CodeClimate badge to the README.md
Added Gemnasium badge to README.md
Fixed link to Code Climate in README.md
Use 'get' instead of 'match' in config/routes
Use strong_parameters
Use \A and \z in regexes
fix use of valid_params in PostsController