Use retriable 1.x

Retriable version 2.0.0.beta is now released and its API changed.
Google-api-client does not work with the new API.
As a quick fix, specify retriable version in '>= 1.4 < 2.0'
Update README.md
Update README.md
Merge pull request #163 from tomykaira/retriable_no_2.0

Use retriable 1.x
remove version from test .
File is being deleted before each test anyway
Use the app logger and require railtie
Clean up gemspec. We don't support 1.8.6 anyway
Replace deprecated method that cause ruby warnings File.exit?
So many versions!!
Another form of Googol typo ?
RSpec 3 syntax
prefer AS's Inflector over Extlib
Drop support for old rubies
Use ActiveSupport instead of extlib
Dropped uuidtools