Fix the locale so tests are deterministic.

Pulled out of https://github.com/apache/incubator-brooklyn/pull/211 (after merging with https://github.com/apache/incubator-brooklyn/pull/220) to fast track the merge to master.
This is changing super.setUp to be `@BeforeClass` rather than `@BeforeMethod` (and same for `super.tearDown`). Is that really what is wanted? We might get away with it in this test class, but would feel better to declare two new methods like `@BeforeClass public void setUpClass() ...`, which just did the localeFix.setUp()`. Thoughts?