Creates and migrates user and shortened url tables
Adds User and ShortenedUrl classes with  associations
Creates ShortenedURL class and factory methods
Adds Visit table and class, Visit::record_visit
Adds numclicks. numuniques, numrecentuniques
Adds cli functionality and Launchy gem
Adds TagTopic and Tag classes, connects to ShortenedUrl
Adds url length check
Adds check for 5 urls in one minute