Swapping out Grunt for Gulp

package.json

@@ -4,7 +4,7 @@
   "version": "0.1.0",
   "main": "src/server.rb",
   "scripts": {
-    "grunt": "grunt"
+    "gulp": "gulp"
   },
   "repository": {
     "type": "git",
@@ -18,11 +18,11 @@
   "author": "Gregory Ballantine <gballantine@bitgoblin.tech>",
   "license": "BSD-2-Clause",
   "devDependencies": {
-    "grunt": "^1.6.1",
-    "grunt-cli": "^1.4.3",
-    "grunt-contrib-coffee": "^2.1.0",
-    "grunt-contrib-sass": "^2.0.0",
-    "grunt-contrib-watch": "^1.1.0",
-    "sass": "^1.77.4"
+    "gulp": "^5.0.1",
+    "gulp-coffee": "^3.0.3",
+    "gulp-plumber": "^1.2.1",
+    "gulp-sass": "^6.0.1",
+    "gulp-sourcemaps": "^3.0.0",
+    "sass": "^1.89.2"
   }
 }