Update tests.

Keep watching a workflow with modularity-testing-framework will be stable.

tests/config.yaml

@@ -2,20 +2,10 @@ document: modularity-testing
 version: 1
 name: ruby
 modulemd-url: https://src.fedoraproject.org/cgit/modules/ruby.git/plain/ruby.yaml
-service:
-    port: 8080
-packages:
-    rpms:
-        # add which here because of the issue.
-        # https://pagure.io/modularity-testing-framework/issue/45
-        - ruby
-testdependecies:
-    rpms:
-        - which
-        - hostname
 module:
-    docker:
-        container: docker.io/ruby
     rpm:
         repos:
-            - http://mirror.vutbr.cz/fedora/releases/25/Everything/x86_64/os/
+            - http://mirror.vutbr.cz/fedora/releases/26/Everything/x86_64/os/
+test:
+    version:
+        - 'ruby -v'