Parallel tests support

[antoinemeyer]

Introduces parallel test support (#4) (and fixes #12)

As of 968e6e4 (https://github.com/antoinemeyer/mock-in-bean/releases/tag/boot2-v2.0-RC), this branch is currently deployed on maven central under:

<dependency>
    <groupId>com.teketik</groupId>
    <artifactId>mock-in-bean</artifactId>
    <version>boot2-v2.0-RC</version>
    <scope>test</scope>
</dependency>

Will be merged to master (and deployed under version boot2-v2.0) after RC has been thoroughly tested.

[antoinemeyer]

replaced by #15