Remove get_version function

- Return all version irrespective of whether version is non digit

onadata/libs/serializers/xform_serializer.py

@@ -356,17 +356,12 @@ def get_has_id_string_changed(self, obj):
 class XFormListSerializer(serializers.Serializer):
     formID = serializers.ReadOnlyField(source='id_string')
     name = serializers.ReadOnlyField(source='title')
-    version = serializers.SerializerMethodField()
+    version = serializers.ReadOnlyField()
     hash = serializers.ReadOnlyField()
     descriptionText = serializers.ReadOnlyField(source='description')
     downloadUrl = serializers.SerializerMethodField('get_url')
     manifestUrl = serializers.SerializerMethodField('get_manifest_url')
 
-    @check_obj
-    def get_version(self, obj):
-        if obj.version and obj.version.isdigit():
-            return obj.version
-
     @check_obj
     def get_url(self, obj):
         kwargs = {'pk': obj.pk, 'username': obj.user.username}