fix script/local to work with .travis.yml changes

& raise an error when a version can’t be found
Throw error when gem adapters loaded w/out correct/any version

This won’t help #3128 since initializers are loaded before routes, but
it would’ve made the solution to #3131 clear.
update AA::Dependencies to use method_missing

so it can handle arbitrary gem names without having to be set up first
Dependencies -> Dependency
update filter hooks to work when Devise is missing

https://github.com/gregbell/active_admin/pull/3041#issuecomment-42960939
attributes_table_for: check if association exists

resolves #2917
exclude gems from SimpleCov stats on Travis

https://github.com/lemurheavy/coveralls-public/issues/296
update travis_cache to work around travis-ci/travis-ci#2321

The S3 bucket permissions now allow downloading files anonymously, but
still require permissions to upload.
travis_cache: don't needlessly download app SHA
simplify CanCan adapter method
Set date format in datepicker input to language format
Set date format in filter data range input to language format
Solution for getting jQuery datepicker to use date format from yaml file
added dutch datepickers format