correct link for SubEthaEdit 3.5.4

former (unversioned) link was broken
Merge pull request #4974 from rolandwalker/sub_etha_edit_3.5.4

correct url for SubEthaEdit 3.5.4
update minitest gem to 5.3

Sync up with Homebrew.  Solves the following problem:
```bash
$ bundle exec rake test
... minitest/unit.rb:19:in `const_missing': uninitialized constant MiniTest::Test (NameError)
	from /usr/local/Library/Homebrew/test/testing_env.rb:91:in `<module:Homebrew>'
    ...
```
disable minitest-colorize

solves this error:
```bash
$ bundle exec rake test
...lib/minitest/colorize.rb:88:in `<top (required)>': undefined method `output=' for Minitest::Unit:Class (NoMethodError)
...
```
define global `shutup` method (temporary)

solves the following error:
```bash
$ bundle exec rake test
...
NoMethodError: undefined method `shutup'
...
```

This is not a permanent solution.  The test suite should be changed
around to find the new `shutup` method, which is still in Homebrew,
but no longer global.
Merge pull request #4982 from rolandwalker/test_env_changes

Adjust to Homebrew's test environment changes
Upgrade radiant player to v1.2.1
Merge pull request #4985 from kevinoconnor7/radiant-player-1-2-1

Upgrade radiant player to v1.2.1
don't check error code of `diskutil eject`

nstead, determine success by directly testing the intended effect:
does the mount path still exist?

Also:
 - retry once on failure.
 - silent success if the given mount point did not exist.

These changes are intended to help with unpredictable problems with
the test suite that manifest frequently on Travis.

References: #4975, #4900, #4857
rubymine 6.3.3
Merge pull request #4987 from chulkilee/rubymine-6.3.3

rubymine 6.3.3
Merge pull request #4978 from rolandwalker/eject_error_code

don't check error code of diskutil eject
refactor `brew cask cleanup`

Divide into more tractable methods. No functional change.
detect cached downloads in doctor

and recommend "brew cask cleanup" if present.

Closes #4857