server: Initial stab at e2e tests (#534)

Initial end to end testing. generates unique names for user and groups, and all tests run serially

server/tests/queries/create_group.graphql

@@ -0,0 +1,6 @@
+mutation CreateGroup($name: String!) {
+  createGroup(name: $name) {
+    id
+    displayName
+  }
+}