Deletes openshift from core

- moved to https://github.com/cloudsoft/brooklyn-openshift

Note that 0.1.0-snapshot is built against brooklyn 0.7.0-snapshot, and is pushed to sonatype (`https://oss.sonatype.org/index.html#nexus-search;quick~brooklyn openshift`)

    <dependency>
      <groupId>io.cloudsoft.systems.openshift</groupId>
      <artifactId>brooklyn-systems-openshift-paas</artifactId>
      <version>0.1.0-SNAPSHOT</version>
    </dependency>