Stop casting likelihood to an integer

From what I can gather, there was a time when likelihood and gpstime
were integers for CWB events, and so there was an explicit casting of
them to integers. Brandon removed gpstime, but left in likelihood
before during ER6. Oops.

gracedb/events/translator.py

@@ -398,12 +398,6 @@ class Translator(object):
         raise(NotImplemented)
 
     def castData(self, data):
-        # convert ints to ints
-        # No longer casting gpstime to integer.
-        #for key in ['gpstime', 'likelihood']:
-        for key in ['likelihood']:
-            if data[key]:
-                data[key] = int(float(data[key]))
 
         # convert floats to floats
         for key in ['far']: