Paperclip works well with aws-sdk 1 and 2, and we default to 2.

[ci skip]

  $ rspec spec/paperclip/integration_spec.rb --profile 1
  Testing against version 4.1.7
  ..................................

  Finished in 15.19 seconds (files took 0.60155 seconds to load)
  34 examples, 0 failures

  Top 1 slowest examples (9.54 seconds, 62.8% of total time):
    Paperclip Many models at once does not exceed the open file limit
      9.54 seconds ./spec/paperclip/integration_spec.rb:18

to

  $ rspec spec/paperclip/integration_spec.rb --profile 1
  Testing against version 4.1.7
  ..................................

  Finished in 10.95 seconds (files took 0.59585 seconds to load)
  34 examples, 0 failures

  Top 1 slowest examples (5.33 seconds, 48.7% of total time):
    Paperclip Many models at once does not exceed the open file limit
      5.33 seconds ./spec/paperclip/integration_spec.rb:18

Updates gemfiles to Ruby 2 hash syntax.

[closes #1700]

Remove from Travis JRuby and Rubinius

They are allowed to fail, and they consistently fail. They only add up
time to our builds. If we wanted to keep them, they should be in the
build matrix and run tests successfully.

Removes note for running paperclip in EOL'd version of Rails (2.3).

Removes `column_type` and `column_options` so that it works well in both
versions.

Backcported from master, to release a patch version with this bugfix.

[closes #1947]

[fixes #1977]

README updated (for Debian-based Linux distros)

Other Debian based distros add in Ubuntu installation line

Test against Ruby 2.2.3 on Travis.

Removes `column_type` and `column_options` so that it works well in both
versions.

[closes #1947]

This reverts commit f6f5ea1b.

[closes #1966]

[closes #1965]

[fixes #1967]

Turns out it didn't fix test failures like I thought. It only added
more!

This reverts commit b8221c6b.

Cucumber needs to tell FakeWeb the s3_domain_url path for uploading a file, and FakeWeb needs to return XML

Both v1 and v2 of the AWS Ruby SDK accept the string literal AES256, no need to differentiate. (thank you, @trevorrowe)