Add JJB template for static code analysis by Coverity Scan service

Add JJB template for static code analysis by Coverity Scan service

"onap-gerrit-maven-coverity" JJB template runs 'mvn clean install' and then
publishes results to Coverity Scan service for static code analysis.

Usage example:

- project:
    name: so-coverity
    jobs:
      - onap-gerrit-maven-coverity
    cron: '@daily'
    build-node: 'ubuntu1604-builder-4c-4g'
    project: 'so'
    project-name: 'so'
    branch: 'master'
    mvn-settings: 'so-settings'
    mvn-goals: 'clean install'
    mvn-opts: '-Xmx1024m -XX:MaxPermSize=256m'
    mvn-params: '-Dmaven.test.skip=true'
    coverity-project-name: 'onap-so'
    coverity-token: 'PUT COVERITY TOKEN HERE'
    coverity-user-email: 'PUT USER EMAIL HERE'

Issue-ID: CIMAN-260

Signed-off-by: Artem Naluzhnyy <A.Naluzhnyy@samsung.com>
Change-Id: I6f4fa6359b5be91932c5a1a1ed7ba0a4068ac152