cleanup travis ci configuration
move Gemfile, add `:integration` group
rubocop style updates
update deprecated berkshelf source format
more strict foodcritic checks
update test-kitchen arguments
don't fail CI run due to missing rake tasks
Support encrypted_password in the pg_user recipe
add contribution from @brainopia to the README
Change encoding/locales to match

I'm not _exactly_ sure why, but the utf8 settings for encoding and locale caused an error when I tried to use them (using postgresql 9.3). Changing those settings to `UTF-8` fixed the issue and made the correct database with encodings.
remove BitDeli badge
add contribution from @tpitale to README
expand individual test steps for CI:

* easier to see return status of each step
use past tense for integration tests
more detailed package output
remove helper which is no longer needed
loosen default chef version constraint
add support for minitest-handler verification
include readme documentation on how to use cfg_update_action