docs: fixing header warning

This warning was being thrown by the linter

```
Checking file headers
1 files have incorrect boilerplate headers:
test/integration/secondary_ranges/controls/inspec_attributes.rb
```

test/integration/secondary_ranges/controls/inspec_attributes.rb

@@ -1,3 +1,17 @@
+# Copyright 2019 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 project_id   = attribute('project_id')
 network_name = attribute('network_name')