Travis CI: a separate script to run test tasks

this script is intended only for use in Travis CI and contains
configuration of the test run requested:

    * it can run linter step separately by specifying TASK_TO_RUN="lint"
      environment variable in .travis.yml. In this case it also runs
      pep8 checker on the commits in PR.
    * other steps are run in developer mode in order to skip pylint run
      and speed up the task
    * in all cases the CI result log is populated and can be displayed
      if the job fails

Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>
Reviewed-By: Fraser Tweedale <ftweedal@redhat.com>

.travis_run_task.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+# NOTE: this script is intended to run in Travis CI only
+set -ev
+
+test_set=""
+developer_mode_opt="--developer-mode"
+
+if [[ "$TASK_TO_RUN" == "lint" ]]
+then
+    if [[ "$TRAVIS_EVENT_TYPE" == "pull_request" ]]
+    then
+        git diff origin/$TRAVIS_BRANCH -U0 | pep8 --diff &> $PEP8_ERROR_LOG ||:
+    fi 
+
+    # disable developer mode for lint task, otherwise we get an error
+    developer_mode_opt=""
+fi
+
+if [[ -n "$TESTS_TO_RUN" ]]
+then
+    pushd ipatests
+    test_set=`ls -d -1 $TESTS_TO_RUN 2> /dev/null | tr '\n' ' '`
+    popd
+fi
+
+docker pull $TEST_RUNNER_IMAGE
+
+ipa-docker-test-runner -l $CI_RESULTS_LOG \
+    -c $TEST_RUNNER_CONFIG \
+    $developer_mode_opt \
+    --container-image $TEST_RUNNER_IMAGE \
+    --git-repo $TRAVIS_BUILD_DIR \
+    $TASK_TO_RUN $test_set