Add default values for env variables (TestRail)

There are commonly used variables ENV_NAME and ISO_PATH
which are required for template based tests initialization.

Change-Id: I507afbc58c6c4968e5f023efb690807f565bf5eb
Closes-bug: #1521986

fuelweb_test/testrail/settings.py

@@ -24,6 +24,9 @@ logger.setLevel(logging.INFO)
 
 LOGS_DIR = os.environ.get('LOGS_DIR', os.getcwd())
 
+os.environ["ENV_NAME"] = "some_environment"
+os.environ["ISO_PATH"] = "./fuel.iso"
+
 JENKINS = {
     'url': os.environ.get('JENKINS_URL', 'http://localhost/'),
     'version_artifact': os.environ.get('JENKINS_VERSION_ARTIFACT',