message: CHANGELOG: Remove superfluous "A " in TestHelper entry
diff: @@ -13,7 +13,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
  ## [Unreleased]
  ### Added
  - Chat system access denial unit tests. [#989](https://github.com/geli-lms/geli/issues/989)
  -- A `TestHelper` class for shared API unit test functionality. [#989](https://github.com/geli-lms/geli/issues/989)
  +- `TestHelper` class for shared API unit test functionality. [#989](https://github.com/geli-lms/geli/issues/989)
  ### Changed
  - Update mongoose to 5.2.x. [#1004](https://github.com/geli-lms/geli/pull/1004)
  