DATACMNS-441 - Fixed potential NullPointerException in query method detection on Java 8 compiled code.

We now skip bridge methods for query method processing in order to circumvent the changed behavior of Class#getMethods() in Java 8 (when the code was compiled with target byte code level 1.8). On Java 8 this results in bridge methods being found and inspected for query method annotations. Since we currently cannot analyze generic return types of bridge methods this results in NullPointerExceptions being thrown at a later stage in AbstractRepositoryMetadata#getReturnedDomainClass(…).

Original pull request: #64.
Related issue: DATAJPA-465.