chore(build): erase redundancies in some pom.xml files

Import of the repository into Eclipse raises some warnings:
- GroupId is duplicate of parent groupId
- Overriding managed version 1.0.0.CR3 for arquillian-weld-ee-embedded-1.1
- Overriding managed version 1.0.0.CR7 for arquillian-junit-container
- Overriding managed version 1.4.1 for mail
- Overriding managed version 2.3.0 for groovy-all
- Overriding managed version 4.11 for junit
- Overriding managed version 7.2.0-SNAPSHOT for camunda-ejb-client
- Overriding managed version 7.2.0-SNAPSHOT for camunda-engine
- Overriding managed version 7.2.0-SNAPSHOT for camunda-engine-spring	pom.xml
- Version is duplicate of parent version
This PR removes these warnings.
The only remaining one then is 'maven-enforcer-plugin (goal "enforce") is ignored by m2e.'