message: style: require braces for all control statements
  I was surprised to learn recently that the Google style guide does not
  actually require this!
diff: In most cases tests can and should be structured so this is not necessary.
  * Tests default to StrictMock so will fail if hitting unexpected warnings. Feel free to use
  NiceMock for mocks whose behavior is not the focus of a test.
  -* There are probably a few other things missing from this list. We will add them as they
  - are brought to our attention.
  * [Thread
  annotations](https://github.com/abseil/abseil-cpp/blob/master/absl/base/thread_annotations.h),
  such as `GUARDED_BY`, should be used for shared state guarded by
  rather than using the 'static' keyword. Note that the
  [Google C++ style guide](https://google.github.io/styleguide/cppguide.html#Unnamed_Namespaces_and_Static_Variables)
  allows either, but in Envoy we prefer annonymous namespaces.
  +* Braces are required for all control statements include single line if, while, etc. statements.
  # Error handling
  