Improve test coverage

Quick fix for flapping behavior on 1.8

Ran the test 10 times over and it was successful each time

This reverts commit c3c4d4ab, reversing
changes made to 4b48bf15.

Conflicts:
	test/test.rb

Merge branch 'improve_test_coverage' of github.com:presidentbeef/brakeman into improve_test_coverage

Fix scope calls with single arguments

Report specific model when rendering collections

instead of "UnknownModel"

Check for overridden initializer values

Merge branch 'improve_test_coverage' of github.com:presidentbeef/brakeman into improve_test_coverage

Conflicts:
	test/tests/test_differ.rb

Don't worry about test coverage on code that is essentially external

for test coverage

closes #153

Treat models and arrays of models as safe input to redirect_to

fixes #143

instead of just an empty string. This should happen almost never, but
hopefully this will prompt people to report bugs if it does happen
instead of hiding them.