Support older versions of Node.

For now!

Author: octalmage

package-lock.json

@@ -41,7 +41,7 @@
     "prebuild-install": "^2.1.1"
   },
   "devDependencies": {
-    "jasmine": "^3.0.0",
+    "jasmine": "^2.99.0",
     "prebuild": "v6.1.0",
     "targetpractice": "0.0.7"
   }

package.json

@@ -5,7 +5,7 @@ var os = require('os');
 
 robot.setMouseDelay(100);
 
-let target, elements;
+var target, elements;
 
 describe('Integration/Keyboard', () => {
 	beforeEach(done => {

test/integration/keyboard.js

@@ -5,7 +5,7 @@ var os = require('os');
 
 robot.setMouseDelay(100);
 
-let target, elements;
+var target, elements;
 
 describe('Integration/Mouse', () => {
 	beforeEach(done => {
@@ -43,7 +43,7 @@ describe('Integration/Mouse', () => {
 			 *  TODO: This is gross! The scroll distance is different for each OS. I want
 			 *  to look into this further, but at least these numbers are consistent.
 			 */
-			let expectedScroll;
+			var expectedScroll;
 			switch(os.platform()) {
 				case 'linux':
 					expectedScroll = 180;

test/integration/mouse.js

@@ -1,7 +1,7 @@
 /* jshint esversion: 6 */
 var robot = require('../..');
 var targetpractice = require('targetpractice/index.js');
-let elements, target;
+var elements, target;
 
 describe('Integration/Screen', () => {
 	beforeEach(done => {