Try to connect in Begin() too. Postpone error handling to Interceptor.

This change will improve Mongo and Revel plays nicer together in case Mongo is not started yet or restarted while Revel is running.

Dial() error is postponed until the Before() interceptor and Revel won't panic any longer.
Switched to config.stringdefault and warn when connection fails upon startup
Adding testapp and travis ci file
Adding travis-ci build status
Fixing revel travis declaration
Optimizing Begin() interceptor to only call a pointer

Before it used a switch statement on strings for every
request which is not necessary since the method (new/clone/copy)
will never change during the runtime)
Fixed error with wrong config name.

Fixes #6
Update .travis.yml

robfig changed to revel
Update .travis.yml

Fixing import paths
Run this repo's tests for Travis
Revert test import path
Fixing the tests rename robfig -> revel
Next try with hardcoded path
Revert path change
Fixed app.conf
Fix test expectations
Getting MONGOHQ_URL