Validating the codecov script when downloading. (#1549)

* Switching to use a wrapper around the codecov script that performs validation in order to prevent data breaches in the future.

.travis.yml

@@ -46,7 +46,7 @@ script:
     fi
 
 after_success:
-  - bash <(curl -s https://codecov.io/bash)
+  - bash <(curl -s https://raw.githubusercontent.com/broadinstitute/codecov-bash-uploader/main/codecov-verified.bash)
   - echo "TRAVIS_BRANCH='$TRAVIS_BRANCH'";
     echo "JAVA_HOME='$JAVA_HOME'";
     if [ "$TRAVIS_BRANCH" == "master" ]; then