Re-enable integration tests for release Firefox
Re-enable integration tests for release Firefox

Issue #2536

lmorchard/idea-town-server,flodolo/testpilot,lmorchard/testpilot,meandavejustice/testpilot,lmorchard/idea-town,chuckharmston/testpilot,lmorchard/idea-town,chuckharmston/testpilot,meandavejustice/testpilot,lmorchard/testpilot,chuckharmston/testpilot,fzzzy/testpilot,meandavejustice/testpilot,flodolo/testpilot,fzzzy/testpilot,fzzzy/testpilot,lmorchard/idea-town-server,lmorchard/idea-town,flodolo/testpilot,lmorchard/testpilot,fzzzy/testpilot,lmorchard/testpilot,mozilla/idea-town,mozilla/idea-town,meandavejustice/testpilot,chuckharmston/testpilot,lmorchard/idea-town,mozilla/idea-town-server,mozilla/idea-town-server,mozilla/idea-town,mozilla/idea-town-server,flodolo/testpilot,mozilla/idea-town-server,lmorchard/idea-town-server,lmorchard/idea-town-server,mozilla/idea-town