Cache Bundler to S3 on Travis
Workaround for CSV#generate encoding issue.
Add integration tests
maybe the latest Bundler isn't needed anymore?
Cache the test app to S3 on Travis
turns out tar remembers the folder structure!
create proper URLs
actually save files when `:as` isn't provided
update `rake setup` to not run if test app exists
Add encode options
add no-default-user option to active_admin:devise generator

When using active admin with a customized User model living in the
main app, it is common to add further validations for profile
attributes etc. Creating a user in the generated migration may fail
then since not all required attributes are present.

In those cases it's better to setup the initial user via a database
seed. This option allows other engines, which bundle active admin, to
invoke default active admin generators while still providing their
default user via a seed.
Refactor dependency checking to use requirement strings
Make devise soft dependency

Load devise only when the dependency is fulfilled. Show an error
message when running generator without devise gem.

Fixes #542.
Add runtime check for Devise version
Merge pull request #3117 from codevise/no-default-user-generator-option

add no-default-user option to active_admin:devise generator
Merge pull request #3041 from lautis/devise-soft-dependency

Conflicts:
	lib/active_admin/resource_controller/decorators.rb
Merge pull request #3097 from dtaniwaki/encoded-csv-workaround

Workaround for CSV#generate encoding issue.
record SHA changes in the console output
alphabetically sort files to be checked
Merge pull request #3095

Conflicts:
	.travis.yml