minor json fixes that caused the docker server to return 500s

docker/client.py

@@ -25,16 +25,16 @@ class Client(requests.Session):
         volumes=None, volumes_from=None):
         return {
             'Hostname':     hostname,
-            'PortSpecs':    ports,
+            'PortSpecs':    [ports],
             'User':         user,
             'Tty':          tty,
             'OpenStdin':    stdin_open,
             'Memory':       mem_limit,
-            'AttachStdin':  0,
-            'AttachStdout': 0,
-            'AttachStderr': 0,
+            'AttachStdin':  False,
+            'AttachStdout': False,
+            'AttachStderr': False,
             'Env':          environment,
-            'Cmd':          command,
+            'Cmd':          [command],
             'Dns':          dns,
             'Image':        image,
             'Volumes':      volumes,