check deflater content type
deflate type check against Rack::Mime::MIME_TYPES

- Rack::Mime::MIME_TYPES
  - now has 604 "file type" => "mime" maps
  - these 604 maps include 535 MIME types
  - all MIME types should deflate or not list in content_type_deflate_expectation
- fix typo
  content_type_deflate_expection -> content_type_deflate_expectation
...except after c.
Test an object which repsonds to each instead of a set.
Utils tests now accept different query orders.
Don't implicitly respond with index file. Fixes #301
Add build and dependency status images to README
Merge pull request #302 from lgierth/rack-static-bug

Don't implicitly respond with index file. Fixes #301
Merge pull request #306 from postmodern/master

Require 'stringio' to fix a NameError in the BodyProxy tests.
Merge pull request #307 from laserlemon/patch-1

Add build and dependency status images to README
Merge pull request #298 from hannesg/tests_should_not_depent_on_set_order

Tests should not depent on set order
Merge pull request #296 from jm3/patch-2

...except after c.
Add missing spec coverage for when secrets do not match (ACHTUNG!)
Fix Rack::Session::Cookie when old_secret or secret are not supplied.
Always encode cookies with one of the two secret options, if provided, preferencing :secret
Based on contribution from ciberch. Closes #304. Closes #299.
Refactoring ip method
Improving a method name
Assert the cookie is secure (there were no tests for this).
Merge pull request #312 from josevalim/assert_secure

Assert the cookie is secure (there were no tests for this).
Rack::BodyProxy should execute block even on failures.

In general, Rack frameworks are moving logic to close hooks in order
to support async behavior increasing the chance an exception will
happen on close. Most servers will actually die if there is an exception
on close, but such exceptions can also happen in the test environment.
In such cases, we can accidentally leave a mutex locked, a database
connection not collected and so forth, therefore, we need to ensure
the block is called regardless closing the body failed.
Merge pull request #313 from josevalim/ensure_proxy

Rack::BodyProxy should execute block even on failures.
prevent crash when session cookie value does not contain "--" delimiter