Some adjustments.

package.json

@@ -1,5 +1,5 @@
 {
-  "name": "gragir.js",
+  "name": "gragir",
   "description": "EPUB v3 generator.",
   "version": "0.1.0",
   "homepage": "https://github.com/vishap/gragir.js",
@@ -20,7 +20,7 @@
       "url": "https://github.com/vishap/gragir.js/blob/master/LICENSE-MIT"
     }
   ],
-  "main": "lib/gragir.js",
+  "main": "lib/gragir",
   "engines": {
     "node": "10.14.2"
   },
@@ -28,12 +28,12 @@
     "test": "grunt nodeunit"
   },
   "devDependencies": {
+    "grunt": "^1.0.3",
     "grunt-contrib-concat": "~0.3.0",
-    "grunt-contrib-uglify": "~0.2.0",
-    "grunt-contrib-jshint": "~0.6.0",
+    "grunt-contrib-jshint": "^2.0.0",
     "grunt-contrib-nodeunit": "~0.2.0",
-    "grunt-contrib-watch": "~0.4.0",
-    "grunt": "~0.4.5"
+    "grunt-contrib-uglify": "^4.0.0",
+    "grunt-contrib-watch": "^1.1.0"
   },
   "keywords": []
-}
+}