Merge pull request #46 from tumblr/activity-category

Adds the correct activity category for Tumblr.

Author: irace

TMTumblrSDK/Activity/TMTumblrActivity.m

@@ -26,4 +26,10 @@ - (UIImage *)activityImage {
 	return [UIImage imageNamed:@"UIActivityTumblr"];
 }
 
+#ifdef __IPHONE_7_0
+- (UIActivityCategory)activityCategory {
+    return UIActivityCategoryShare;
+}
+#endif
+
 @end