Remove Gemfile.lock

Gems shouldn't include a Gemfile lock, so remove it.

At the same time, update the gemspec to include the exact dependencies,
so that we can still pin dependencies to the desired version.

Change-Id: I81b3cc2304f036d15b2923f7b35a32b6fe7fc5c0
Reviewed-on: https://gerrit.causes.com/33025
Reviewed-by: Shane da Silva <shane@causes.com>
Tested-by: Shane da Silva <shane@causes.com>
Upgrade RSpec 2.6.0 -> 2.14.1

Buffet hasn't had it's version of RSpec updated in a long time. Update
it now and fix any deprecation warnings.

Change-Id: I0b6ea685189cd472bfbee3c4476d577d4578b49a
Reviewed-on: https://gerrit.causes.com/33026
Reviewed-by: Shane da Silva <shane@causes.com>
Tested-by: Shane da Silva <shane@causes.com>