Add another shard to be able to run all the tests.

.travis.yml

@@ -24,13 +24,13 @@ install:
 env:
   - MAKE_TARGET=test.syntax
   - MAKE_TARGET=test.edx_east_roles
-  - MAKE_TARGET=docker.test.shard SHARD=0 SHARDS=3
-  - MAKE_TARGET=docker.test.shard SHARD=1 SHARDS=3
-  - MAKE_TARGET=docker.test.shard SHARD=2 SHARDS=3
+  - MAKE_TARGET=docker.test.shard SHARD=0 SHARDS=4
+  - MAKE_TARGET=docker.test.shard SHARD=1 SHARDS=4
+  - MAKE_TARGET=docker.test.shard SHARD=2 SHARDS=4
+  - MAKE_TARGET=docker.test.shard SHARD=3 SHARDS=4
 
 script:
   - docker --version
   - make --version
-  - set -x
   # TODO: move this back down to 50 once we are on ansible 2.x
   - travis_wait 90 make --keep-going $MAKE_TARGET SHARD=$SHARD SHARDS=$SHARDS