Add more testing rake tasks

Add convenience tasks to run tests across the gemfiles for rails 3.0, 3.1, and 3.2.
Update travis config

Remove 1.8.7 and ree because I can't get them to pass on travis.
I'll restore them when I figure out travis.
Update Manifest and gemspec
Bump minitest dependency version
Move VERSION its own file

So it can be shared between the gem and autotest config.
Version bump for 0.3 release
Allow "Widget\s?Acceptance" and "Widget\?Integration" too.

Call register_spec_type only once.

Merged the two regexps.
Merge pull request #84 from haihappen/regexps

Update spec name regex to make "Test" optional.
Avoid deprecation warning in Mocha 0.13.0.

I'm not entirely sure why this code is duplicated from ActiveSupport,
but this deprecation warning has been fixed in 3-2-stable [1] and in
master [2].

[1] https://github.com/rails/rails/pull/8200
[2] https://github.com/rails/rails/pull/8180
Merge pull request #85 from freerange/fix-mocha-deprecation-warning

Avoid deprecation warning in Mocha 0.13.0.
update minitest_helper template to fix typo, clarify
Merge pull request #90 from montague/fix-minitest-template-typo

update minitest_helper template to fix typo, clarify
Extract logic to MiniTest::Rails::Testing

Use MiniTest::Rails::Testing.default_tasks instead of MINITEST_TASKS.
Override ActiveSupport::TestCase by default

This is a big change that simplifies the approach to how minitest is integrated.
Use ActiveSupport::TestCase instead of MiniTest::Rails::ActiveSupport::TestCase.
Instead of maintaining separate TestCase objects, overwrite the standard objects.
Focus only on on what is needed to enable minitest and the spec DSL.
Remove the MiniTest::Rails:: prefix from the generated tests.
Update gemfiles

Use the most recent versions with the recent security fixes.
Add early support for Rails 4
Remove acceptance

Rails Core has spoken and these tests are going to be known as integration. No change.
Improved readability of README
Merge pull request #91 from muellerj/patch-1

Update README

Add markup around minitest constants in README.
Update generator base

Backfill methods missing from different versions of Rails without version checking soup.