Remove redundant test

Closes #454.

I believe this test was intended to refer to the exception [1] raised in
`Mockery#verify` i.e. ExpectationError [2] when using Test::Unit and
MiniTest::Assertion [3] when using MiniTest.

When an unexpected invocation is received by a mock object, it raises
the same type of exception (see Mock#raise_unexpected_invocation_error
[4]). Thus the scenario for an unexpected invocation earlier in the same
test case gives us some related coverage.

I believe the reason why we don't want the exception class to be rescued
by a standard `rescue` is that the code under test could legitimately
include such a rescue block. If the Mocha-generated exception was
rescued by the code under test, the test failure might be swallowed or a
confusing error message might be displayed. It's much less legitimate
for code under test to rescue `Exception` and so it's preferable if the
Mocha-generated exception is a direct subclass of `Exception` and not
`StandardError`.

Having said all that the test in question is not really testing anything
useful that isn't tested elsewhere.

[1]: https://github.com/freerange/mocha/blob/8751dcbda08650a339932d86c9f24d076c167300/lib/mocha/mockery.rb#L93
[2]: https://github.com/freerange/mocha/blob/8751dcbda08650a339932d86c9f24d076c167300/lib/mocha/expectation_error.rb#L7)
[3]: https://github.com/freerange/mocha/blob/8751dcbda08650a339932d86c9f24d076c167300/lib/mocha/integration/mini_test/adapter.rb#L26
[4]: https://github.com/freerange/mocha/blob/8751dcbda08650a339932d86c9f24d076c167300/lib/mocha/mock.rb#L380)

test/acceptance/exception_rescue_test.rb

@@ -37,17 +37,4 @@ def test_invocation_never_expected_exception_is_not_caught_by_standard_rescue
     assert_failed(test_result)
     assert_equal 'unexpected invocation: #<Mock:mock>.some_method()', test_result.failure_message_lines[0]
   end
-
-  def test_unsatisfied_expectation_exception_is_not_caught_by_standard_rescue
-    test_result = run_as_test do
-      mock = mock('mock')
-      mock.expects(:some_method)
-    end
-    assert_failed(test_result)
-    assert_equal [
-      'not all expectations were satisfied',
-      'unsatisfied expectations:',
-      '- expected exactly once, invoked never: #<Mock:mock>.some_method(any_parameters)'
-    ], test_result.failure_message_lines
-  end
 end