feat(*): add npm script for updating bower dependencies as well

Previously, is was suggested to run `bower update`, which would only work if `bower` was globally
installed. Since a global `bower` installation should not be a prerequisite for the seed project, it
is now possible to update bower dependencies via the new `update-deps` npm script.

Fixes #383

Author: gkalpak

README.md

@@ -185,25 +185,17 @@ If JDK is not already installed, you can download it [here][jdk-download].
 
 ## Updating Angular
 
-Previously we recommended that you merge in changes to angular-seed into your own fork of the project.
-Now that the angular framework library code and tools are acquired through package managers (npm and
-bower) you can use these tools instead to update the dependencies.
-
-You can update the tool dependencies by running:
-
-```
-npm update
-```
-
-This will find the latest versions that match the version ranges specified in the `package.json` file.
-
-You can update the Angular dependencies by running:
+Since the Angular framework library code and tools are acquired through package managers (npm and
+bower) you can use these tools to easily update the dependencies. Simply run the preconfigured
+script:
 
 ```
-bower update
+npm run update-deps
 ```
 
-This will find the latest versions that match the version ranges specified in the `bower.json` file.
+This will call `npm update` and `bower update`, which in turn will find and install the latest
+versions that match the version ranges specified in the `package.json` and `bower.json` files
+respectively.
 
 
 ## Loading Angular Asynchronously

package.json

@@ -19,6 +19,9 @@
   "scripts": {
     "postinstall": "bower install",
 
+    "update-deps": "npm update",
+    "postupdate-deps": "bower update",
+
     "prestart": "npm install",
     "start": "http-server -a localhost -p 8000 -c-1 ./app",