Fix GeoscalingWebClientTest

- Adds comment to GeoscalingWebClient about trust store.
- Was failing due to certificate not in trust store. For tests,
  run with trustAll
- Also convert from groovy to java
Fix GeoscalingIntegrationTest

- it was not instantiating StubHostGeoLookup
Fix SshMachineLocationIntegrationTest

- It needs the brooklyn.properties contents for named location
  “localhost-passphrase”, so can’t just use `newManagedInstanceForTests`
Fix QpidIntegrationTest

- use correct management URL (otherwise get back 404)
Fix NnginxClusterIntegrationTest

- if use initialSize=0, then serviceUp behaves differently when
  cluster is empty. So don’t do that.
Fix MavenArtifactTest

- URLClassLoader does not follow redirects, so need to do that first
  (for URLs pointing at search.maven.org), before seeing if they
  can be resolved correctly
Merge and close #270