Improve jasmine api tests

Remove all of the self defined matchers like toHaveProp, toBeFunction,
etc. and use the ones provided by jamsine. Don't run findServices for
each spec, instead do it once for the main suite and use that one for all
specs.

Jira-issue: WP-725
Merge pull request #446 from aldafu/WP-725-improve-jasmine-tests

Improve jasmine api tests