message: Update CONTRIBUTING.md
  * Update CONTRIBUTING.md
  Edited a few grammar issues.
  * Fix
diff: @@ -41,7 +41,7 @@ TensorFlow coding style.
  #### General guidelines and philosophy for contribution
  * Include unit tests when you contribute new features, as they help to
  - a) prove that your code works correctly, b) guard against future breaking
  + a) prove that your code works correctly, and b) guard against future breaking
  changes to lower the maintenance cost.
  * Bug fixes also generally require unit tests, because the presence of bugs
  usually indicates insufficient test coverage.
  @@ -51,7 +51,7 @@ TensorFlow coding style.
  non-backward-compatible API changes without a major release. Reviewers of your
  pull request will comment on any API compatibility issues.
  * When you contribute a new feature to TensorFlow, the maintenance burden is (by
  - default) transferred to the TensorFlow team. This means that benefit of
  + default) transferred to the TensorFlow team. This means that benefit of the
  contribution must be compared against the cost of maintaining the feature.
  * Full new features (e.g., a new op implementing a cutting-edge algorithm)
  typically will live in
  