test with tsan (#30)

motivation: better testing, safer code

changes: run 5.1 tests with tsan on

Author: tomerd

docker/docker-compose.1604.51.yaml

@@ -11,6 +11,8 @@ services:
 
   test:
     image: swift-aws-lambda:16.04-5.1
+    environment:
+      - SANITIZER_ARG=--sanitize=thread
 
   shell:
     image: swift-aws-lambda:16.04-5.1

docker/docker-compose.yaml

@@ -28,7 +28,7 @@ services:
 
   test:
     <<: *common
-    command: /bin/bash -cl "swift test -Xswiftc -warnings-as-errors"
+    command: /bin/bash -cl "swift test -Xswiftc -warnings-as-errors $${SANITIZER_ARG-}"
 
   # util