Rename insertFirst and insertLast to prependChild and appendChild

Author: Joris-van-der-Wel

lib/SymbolTree.js

@@ -759,14 +759,14 @@ class SymbolTree {
          *
          * `O(1)`
          *
-         * @method insertFirst
+         * @method prependChild
          * @memberOf module:symbol-tree#
          * @param {Object} newObject
          * @param {Object} referenceObject
          * @throws {Error} If the newObject is already present in this SymbolTree
          * @return {Object} newObject
          */
-        insertFirst(newObject, referenceObject) {
+        prependChild(newObject, referenceObject) {
                 const referenceNode = this._node(referenceObject);
                 const newNode = this._node(newObject);
 
@@ -793,14 +793,14 @@ class SymbolTree {
          *
          * `O(1)`
          *
-         * @method insertLast
+         * @method appendChild
          * @memberOf module:symbol-tree#
          * @param {Object} newObject
          * @param {Object} referenceObject
          * @throws {Error} If the newObject is already present in this SymbolTree
          * @return {Object} newObject
          */
-        insertLast(newObject, referenceObject) {
+        appendChild(newObject, referenceObject) {
                 const referenceNode = this._node(referenceObject);
                 const newNode = this._node(newObject);