Zuul: Switch from travis to zuul

This PS adds the skeleton for a set of zuul checks and gates for
airshipctl and removes the travis config.

This PS also removes some dead code from the util package. This change
is required to get unit tests passing.

Change-Id: Ifb1be49cb1bb82c62a0085b6da9b8ff1b261a95b

playbooks/airship-airshipctl-common.yaml

@@ -0,0 +1,14 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+- hosts: all
+  roles:
+    - install-docker

playbooks/airship-airshipctl-lint-test.yaml

@@ -0,0 +1,27 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+- hosts: primary
+  tasks:
+
+    - name: Run Linter
+      block:
+        - name: "make docker-image-lint"
+          make:
+            chdir: "{{ zuul.project.src_dir }}"
+            target: docker-image-lint
+
+    - name: Run Unit Tests
+      block:
+        - name: "make docker-image-unit-tests"
+          make:
+            chdir: "{{ zuul.project.src_dir }}"
+            target: docker-image-unit-tests