Digitalocean no longer needs to be on the python3 blacklist

.travis.yml

@@ -14,9 +14,6 @@ env:
   global:
     # 76 modules.  Let's whittle this down!
     - PY3_EXCLUDE_LIST="cloud/amazon/cloudformation.py
-      cloud/digital_ocean/digital_ocean_domain.py
-      cloud/digital_ocean/digital_ocean.py
-      cloud/digital_ocean/digital_ocean_sshkey.py
       cloud/docker/docker_container.py
       cloud/docker/docker_image_facts.py
       cloud/docker/docker_login.py