Support multiple hostnames on expose label in service for Kubernetes (#1092)

* Support multiple hostnames on label (kompose.service.expose) separated by semicolon (;)

* Multiple hostnames on expose label separated by comma; Ignore leading / trailing spaces and repeated commas; Updated test cases and documents.

script/test/fixtures/expose-service/compose-files/docker-compose-expose-multiple-hostname-tls.yml

@@ -0,0 +1,13 @@
+web:
+  image: tuna/docker-counter23
+  ports:
+    - "5000:5000"
+  links:
+    - redis
+  labels:
+    kompose.service.expose: "batman.example.com,batwoman.example.com"
+    kompose.service.expose.tls-secret: "test-secret"
+redis:
+  image: redis:3.0
+  ports:
+    - "6379"

script/test/fixtures/expose-service/compose-files/docker-compose-expose-multiple-hostname.yml

@@ -0,0 +1,12 @@
+web:
+  image: tuna/docker-counter23
+  ports:
+    - "5000:5000"
+  links:
+    - redis
+  labels:
+    kompose.service.expose: "  batman.example.com ,, batwoman.example.com "
+redis:
+  image: redis:3.0
+  ports:
+    - "6379"