Enable Bionic as a gate test

Change bionic test from dev to gate for 18.05.

Change-Id: Iaddaede55c19231dc23941015c3d8dd7347d583e

src/tests/basic_deployment.py

@@ -94,7 +94,7 @@ class CephFsBasicDeployment(OpenStackAmuletDeployment):
         # Include a non-existent device as osd-devices is a whitelist,
         # and this will catch cases where proposals attempt to change that.
         ceph_osd_config = {
-            'osd-reformat': 'yes',
+            'osd-reformat': True,
             'ephemeral-unmount': '/mnt',
             'osd-devices': '/dev/vdb /srv/ceph /dev/test-non-existent',
             'source': self.source,

src/tox.ini

@@ -35,7 +35,7 @@ commands =
 # Run a specific test as an Amulet smoke test (expected to always pass)
 basepython = python2.7
 commands =
-    bundletester -vl DEBUG -r json -o func-results.json gate-basic-xenial-pike --no-destroy
+    bundletester -vl DEBUG -r json -o func-results.json gate-basic-bionic-queens --no-destroy
 
 [testenv:func27-dfs]
 # Run all deploy-from-source tests which are +x (may not always pass!)