Add additional supported platforms to Subject (close snowplow#172)

Author: miike

snowplow_tracker/subject.py

@@ -21,7 +21,7 @@
 
 from contracts import contract, new_contract
 
-SUPPORTED_PLATFORMS = set(["pc", "tv", "mob", "cnsl", "iot"])
+SUPPORTED_PLATFORMS = set(["pc", "tv", "mob", "cnsl", "iot", "web", "srv", "app"])
 DEFAULT_PLATFORM = "pc"
 
 new_contract("subject", lambda x: isinstance(x, Subject))
@@ -41,7 +41,7 @@ def __init__(self):
     @contract
     def set_platform(self, value):
         """
-            :param  value:          One of ["pc", "tv", "mob", "cnsl", "iot"]
+            :param  value:          One of ["pc", "tv", "mob", "cnsl", "iot", "web", "srv", "app"]
             :type   value:          supported_platform
             :rtype:                 subject
         """