Add badge for CircleCI

Author: pvanheus

README.md

@@ -18,4 +18,6 @@ The `parse_accession.py` script aims to work with all Python versions. The `scra
 script requires at least Python 3.6 and the modules specified in `conda_requirements.txt`.
 
 This code is licensed under the BSD 3 clause license. Please feel free to use and modify the code, but
-it is released without warranty. See the `.py` files for details.
+it is released without warranty. See the `.py` files for details.
+
+[![CircleCI](https://circleci.com/gh/pvanheus/parse_accessions.svg?style=svg)](https://circleci.com/gh/pvanheus/parse_accessions)