Add placeholders to fp wrapper. [closes #1780]

lib/fp/mapping.js

@@ -152,6 +152,16 @@ module.exports = {
     }
   },
 
+  /** Used to track methods with placeholder support */
+  'placeholder': {
+    'bind': true,
+    'bindKey': true,
+    'curry': true,
+    'curryRight': true,
+    'partial': true,
+    'partialRight': true
+  },
+
   /** Used to track methods that skip `_.rearg`. */
   'skipRearg': {
     'assign': true,