* Golang step metadata: Config aliases for steps
This will ease following scenarios:
* config migration due to step name changes
* re-use of more general config, e.g. `mavenExecute` in `mavenBuild`
* fix CodeClimate finding
* Fix panic if original stage config does not exist yet
* add static code checks for maven based projects as:
* pmd plugin
* spotBugs plugin
* test modules as unit-tests and integration-tests will be ignored by default. Additional modules to ignore are configurable
* for pmd: rulesets and excludes are configurable
* for spotBugs: includeFilter and excludeFilter are configurable