Creates model and writes Url Model validation context and description
Setup url factories and write the test to validate the presence of long url
Url model now validates the presence of long url
Writes test to check the validity of given long url
Writes the activerecord validation to validate the format of long_url with regex
Update regex to check http ftp and https
Writes test to check that it shortens the url before save
Long url now gets shortened before being saved
Writes test to validate the uniqueness of short url
Writes activerecord validation to check the uniqueness of short url
Merge pull request #2 from dahal/Url_Model

Url model