Hackebrot convert test find

Convert `test_find.TestFindTemplate` and `test_main.TestFindTemplate2` to `py.test`.

Please give your attention to 0208a38 as I removed some asserts which seem to be redundant. Since we are testing for equality first (`assert template == 'foo'`), I don't see any way how a subsequent test for inequality should fail (`assert template != 'bar'`) without changing `template`.

Let me know your thoughts!