Merge branch 'master' of https://github.com/biowdl/tasks into star

.travis.yml

+language: java
+script:
+  - set -e
+  - wget https://github.com/broadinstitute/cromwell/releases/download/30.2/womtool-30.2.jar
+  - for F in `find -name "*.wdl"`; do java -jar womtool-30.2.jar validate $F; done