Update README

I just released a new version (v1.1.0) of the Fastly gem that includes
your most recent changes. I've updated the README to reflect that
change.
Merge pull request #1 from ezkl/update-readme

Update README
Add Gemfile
Use new Version#upload_main_vcl method
Merge pull request #2 from ezkl/use-new-vcl-upload-method

Use new main VCL upload method