Enable coveralls.

.travis.yml

@@ -4,5 +4,9 @@ python:
 install:
   - pip install --upgrade .
   - pip install pylint
+  - pip install python-coveralls
 script:
   - ./run_presubmit.sh
+after_success:
+  # Upload coverage data to coveralls.io.
+  - coveralls

README.md

@@ -1,7 +1,8 @@
 # GCP Variant Transforms
 
 [![Build Status](https://travis-ci.org/googlegenomics/gcp-variant-transforms.svg?branch=master)](https://travis-ci.org/googlegenomics/gcp-variant-transforms)
-
+[![Coverage
+Status](https://coveralls.io/repos/github/googlegenomics/gcp-variant-transforms/badge.svg)](https://coveralls.io/github/googlegenomics/gcp-variant-transforms)
 
 ## Overview
 

run_presubmit.sh

@@ -18,7 +18,7 @@ set -euo pipefail
 # A helper script for ensuring all checks pass before submitting any change.
 
 echo ========== Running unit tests.
-python setup.py test
+coverage run --source=gcp_variant_transforms setup.py test
 
 echo ========== Running pylint.
 pylint gcp_variant_transforms