Fixed minor typo (wrong module name in example)
Added a small "Account" class that fetches account information

I added the Account class and made sure it is initialised correctly.
Right now, only 2 methods are exposed: list (all accounts) and account
(only your own account)

I had to make some changes in "lib/opsource.rb" to make it import all
needed dependencies correctly (added "./" in front and ".rb" at the
back). I'm using ruby 2.0.
Forgot to add account.rb
Merge pull request #1 from ddccffvv/master

Fixed small typo and added account class