convert message to adaptive cards with colored headers

[jbsil]

related to #25

• put the structure of the adaptive card into a .jq template file. you can use https://adaptivecards.io/designer/ to adjust the "content" section visually.
• the header of the card is visually distinct, if we can find a descriptive word in either the provided title or text content.
  • you can override this by passing a style param
• pulled the Dockerfile apt-gets into separate, earlier, RUN statement to take better advantage of docker build caching (for faster iterations).

[jbsil]

example config:

    on_failure:
      do:
      - put: teams-prs
        attempts: 3
        params:
          title: FAILED - [pipeline or job name] - $BUILD_JOB_NAME for ((.:pr.title))
          text: pr build failed!
          actionName: View Pipeline
          actionTarget: https://my.concourse.url/teams/$BUILD_TEAM_NAME/pipelines/$BUILD_PIPELINE_NAME/jobs/$BUILD_JOB_NAME/builds/$BUILD_NAME
    on_success:
      do:
      - put: teams-prs
        attempts: 3
        params:
          title: PASSED - [pipeline or job name] - $BUILD_JOB_NAME for ((.:pr.title))
          text: pr build passed!
          actionName: View Pipeline
          actionTarget: https://my.concourse.url/teams/$BUILD_TEAM_NAME/pipelines/$BUILD_PIPELINE_NAME/jobs/$BUILD_JOB_NAME/builds/$BUILD_NAME

and the results: