Fix .scrutinizer.yml

The last tests override was cancelling the first.
`coverage` is not found by scrutinizer if not installed here.

.scrutinizer.yml

@@ -11,6 +11,9 @@ build:
         python: 3.6.0
         postgresql: false
         redis: false
+    dependencies:
+        before:
+            - pip install coverage
     tests:
         override:
             -
@@ -19,8 +22,4 @@ build:
                     file: '.coverage'
                     config_file: '.coveragerc'
                     format: 'py-cc'
-    nodes:
-        analysis:
-            tests:
-                override:
-                    - py-scrutinizer-run
+            - py-scrutinizer-run