Update CHANGELOG.md

Co-authored-by: Angeline Burrell <aburrell@users.noreply.github.com>

Author: jklenzing

CHANGELOG.md

@@ -12,7 +12,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
   * Added manual test for pysat and pysatNASA Release Candidates
   * Added manual test for pysatModels RC pip install
   * Updated tests to new pysat and pytest standards
-  * Added cap for pysatNASA
+  * Added a cap for pysatNASA
 * Documentation
   * Added badges and instructions for PyPi and Zenodo