Grunt: gzip library and asset files

- Configure travis to use gzip task
  and set Content-Encoding: gzip header
  in AWS S3 bucket
Update version to v0.3.5
Fix grunt gzip task:

- gzip all lib files
- do not try to overwrite files in
  compress task (instead copy, then clean up dups)
  otherwise task seems to compress the files down
  over and over down to nothing
Update version to 0.3.6