- Also bump Travis Ruby 2.2.x version to 2.2.4

-   Also modify the appraisals to be more flexibly specified.
-   The specs are '>= 1.16' and '< 4.0' because the major versions of
    mime-types have steadily restricted the supported versions of Ruby at a
    different rate than Rails. The Appraisal for Rails 5 can be specified as
    either '>= 2.0, '< 4.0' or '~> 3.0' depending on how other gems restrict
    mime-types versions.

    -   mime-types 1.x supports any version of Ruby, but no longer receives any
        updates (it hit EOL on 27 October 2015).
    -   mime-types 2.x supports Ruby >= 1.9.2, but will only receive security
        and data updates until 21 November 2017.
    -   mime-types 3.x supports Ruby >= 2.0 and is the active development
        version of mime-types.

-   The APIs that paperclip uses are compatible between all three versions of
    mime-types.

  $ 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]

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.

* update aruba methods for in_current_dir and check_file_presence
* switch rspec syntax from should to expect
* configure raise_in_transactional_callbacks if AR >= 4.2
* remove paperclip itself from Appraisal
This also updates Travis to use the default bundler (to enable caching) and to build primary rubies first

Change it from 3.2.15 to 3.2.0. We'll let bundler handle installing the
latest version. With `~>` the last number doesn't really matter anyway.

[houndci](https://houndci.com) was try to add it because I thought set of tools that can be found in the local environment is want I 'm handy when you pull request

As referenced in #1739

Just because the `Rails` constant is defined, it doesn't mean we're
actually in a Rails app. Since there are people who use Paperclip
outside of Rails, and there's no reason we shouldn't be able to run in
those situations. This commit checks for `Rails.env` instead of just
checking for `Rails` and assuming `Rails.env` works.

Turns out that between fog 1.22.0 and fog 1.25.0, there was a change to
how fog builds S3 expiring URLs. This changes to test to be the common
point between the two versions. All we need to do here is make sure that
the expiring URL is being constructed.

In the process, this also updates all the appraisal-generated
Gemfiles.

Also, in the process, this meant I had to take away the builder version
restriction. This was put in so that `bundle`ing wouldn't take forever,
but I'm unsire whether this needed to happen with this version or if
builder just needed to be separate from the Gemfile. I'm commimtting
this and asking the people who reported the problem. If you don't see a
revet commit, everything was fine.

This reverts commit 8e0eb4ce.

During the fixing of the previous commit, the tests broken. Turns out
that between fog 1.22.0 and fog 1.25.0, there was a change to how fog
builds S3 expiring URLs. This changes to test to be the common point
between the two versions. All we need to do here is make sure that the
expiring URL is being constructed.

In the process, this also updates all the appraisal-generated Gemfiles.

Also, in the process, this meant I had to take away the builder version
restriction. This was put in so that `bundle`ing wouldn't take forever,
but I'm unsire whether this needed to happen with this version or if
builder just needed to be separate from the Gemfile. I'm commimtting
this and asking the people who reported the problem. If you don't see a
revet commit, everything was fine.

First off, sqlite3 needs to be exactly v1.3.8.
Need to make sure both racc and rubysl are in the Gemfiles.
RBX's File.join doesn't like nil at all.
RBX also doesn't like to remove a constant that doesn't exist yet.

This is a big one.

This change converts all of the existing tests from test/unit to RSpec.
It's been a long time coming, and was specifically prompted by the
inability of minitest to work with Appraisal across the various Rails
versions. Instead of ironing out that headache, converting to RSpec was
preferable (after initial probing).

Many assertions are still assertions and are housed in the Assertions
module, but they should be converted as they get touched. Similarly,
since we're touching all the tests/specs, we convert all the hashes from
1.8 syntax to 1.9 syntax.

This also removes Pry.

This test will generate a basic Rails application, include Paperclip
into Gemfile, and call basic `has_attached_file` in the model. This will
make sure that we're not messing up any of the configuration and
integration for our gem and the Rails framework.

However, this will make sure that you can always change it to something else afterward.

There's currently no test for this, but after I've tried this with the `integration_test` branch, I can confirm that logs are written to `log/test.log` as it should.

Closes #581

Abstract out the file geometry parser within Thumbnail. This makes it possible to have different cropping and scaling controls, as the papermill gem does.

Bump rails 3_1 version to rc6