Fix cosmetic problems in YAML source

This change corrects problems reported by the `yamllint` linter.

Since key duplication problems were removed in 4d48711, this commit
mainly fixes trailing spaces and extra empty lines at beginning/end of
files.

test/integration/targets/changed_when/meta/main.yml

@@ -1,3 +1,2 @@
-dependencies: 
+dependencies:
   - prepare_tests
-

test/integration/targets/changed_when/tasks/main.yml

@@ -23,7 +23,7 @@
 - debug: var=shell_result
 
 - name: changed should always be true for shell
-  assert: 
+  assert:
     that:
        - "shell_result.changed"
 
@@ -35,8 +35,6 @@
 - debug: var=shell_result
 
 - name: changed should be false
-  assert: 
+  assert:
     that:
        - "not shell_result.changed"
-
-