Support TravisCI tests for multiple databases
Specify decimal scale

The default is 0 but we need floating point value for days_per_point in projects table
This made spec error happen on mysql and postgresql
Fix failure spec derived from sequential 'id'

The id has to be retrieved from the real object instead of depending
the order of creation of the objects because Postgresql does not
initialize the sequential number in each tests.
Merge pull request #65 from kaznum/travis_multiple_db

Multiple DB for TravisCI