Added .travis.yml file

As explained in http://about.travis-ci.org/docs/user/getting-started/
Modification to travis config file

Based on
http://matthew.mceachen.us/blog/how-to-test-your-rails-application-with-travis-ci-on-different-databases-engines-1220.html
Added travis CI build status image in README

Ref: http://about.travis-ci.org/docs/user/status-images/
Further tweaking of travis CI config

http://stackoverflow.com/a/13776019/429758
Moar travis config tweaking

Get the command right for running specs & features
Include mysql gem to enable travis to run it on mysql
Added sqlite3 gem to enable travis to run tests against it
Added mysql2 gem & made it 'rake spec'
Further changes in travis config

Removed mysql portion as I don't have time to debug the failures
Added a separate Gemfile for travis usage
Let's see if this makes travis run bundle install
Showing entries of a runner in descending order of created date
Added ability to delete comment from entry page

- If the user has commented on the entry he will see delete link for
  the comment on entry show page
Remove extra whitespace while calculating name of the user
Merge pull request #15 from prathamesh-sonpatki/order_entries

Showing entries of a runner in descending order of created date
Merge pull request #14 from prathamesh-sonpatki/delete_comment

Added ability to delete comment with a minor change in comment model
pragprog prize info + limiting the size of location text