Specify default content type for GitHub releases

GitHub requires a Content-Type header for uploading release assets;
specify a default of application/octet-stream so that unrecognized files
can be uploaded.
Merge pull request #144 from koterpillar/github-default-content-type

Specify default content type for GitHub releases
Bump to 1.6.5
GCS: Add custom upload path, Content-Type, ACL, Cache-Control, content-encoding options
Move detect_encoding? and encoding_for to provider.rb

And revert removing gcs example at README.md
Add dot_match option to S3 provider

When collecting files to upload, optionally include dot files
Fixes https://github.com/travis-ci/dpl/issues/148
Add dot_match option to cloud_files provider

When collecting files to upload, optionally include dot files
Add dot_match option to gcs provider

When collecting files to upload, optionally include dot files
Document `:dot_match` option for GCS, Rackspace, and S3
Unstash stashed changes before exiting

Changes introduced to the app are cleaned up during deployment,
making them unavailable to after_deploy block.
Since such changes include the bundled gems, after_deploy block
could not use "bundle exec" to interact with the application in
an expected manner.
Merge pull request #149 from travis-ci/ha-bug-unstash-for-after-deploy

Unstash stashed changes before exiting
Add experimental Google App Engine support

See https://github.com/travis-ci/dpl/issues/94
Merge branch 'master' of github.com:travis-ci/dpl
Make GAE available
Merge pull request #145 from keima/feature/gcs-contenttype

GCS: Add custom upload path, Content-Type, ACL, Cache-Control, etc!

Conflicts:
	README.md
	spec/provider/gcs_spec.rb
Merge pull request #153 from travis-ci/test-pr145

Resolve merge conflict with #145