Switch python3 versions of test jobs to match Train PTI

In Train, we will use python 3.6 and 3.7 for python3 runtime
in our gate jobs [1]. This commit also adds python 3.7.
In Python3.7 async is a reserved keyword so replacing it with is_async.

[1] https://governance.openstack.org/tc/reference/runtimes/train.html

Change-Id: I05f40c4a9304cad551cefd4f10c3ba9a72d69a6f

.zuul.yaml

@@ -146,7 +146,7 @@
       - openstack-cover-jobs
       - openstack-lower-constraints-jobs
       - openstack-python-jobs
-      - openstack-python36-jobs
+      - openstack-python3-train-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3
     check:

docker/monasca-api.conf.j2

@@ -443,7 +443,7 @@ max_retry = 1
 #
 # The type of posting
 #  (boolean value)
-async = true
+is_async = true
 
 #
 # Specify if the message received should be parsed.

monasca_api/common/messaging/kafka_publisher.py

@@ -36,7 +36,7 @@ class KafkaPublisher(publisher.Publisher):
         self.topic = topic
         self.group = cfg.CONF.kafka.group
         self.wait_time = cfg.CONF.kafka.wait_time
-        self.async_ = cfg.CONF.kafka.async
+        self.is_async = cfg.CONF.kafka.is_async
         self.ack_time = cfg.CONF.kafka.ack_time
         self.max_retry = cfg.CONF.kafka.max_retry
         self.auto_commit = cfg.CONF.kafka.auto_commit

monasca_api/conf/kafka.py

@@ -60,7 +60,7 @@ The number of retry when there is a connection error
                 advanced=True, help='''
 Should messages be automatically committed
 '''),
-    cfg.BoolOpt('async', default=True,
+    cfg.BoolOpt('is_async', default=True,
                 help='''
 The type of posting
 '''),

setup.cfg

@@ -17,6 +17,7 @@ classifier =
     Programming Language :: Python :: 2
     Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3.6
+    Programming Language :: Python :: 3.7
 
 [files]
 packages =

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,pep8,cover
+envlist = py27,py37,pep8,cover
 minversion = 2.7
 skipsdist = True