How to install npm peer dependencies automatically? : <p>For example, when I install Angular2:</p>

<pre><code>npm install --save angular2
temp@1.0.0 /Users/doug/Projects/dougludlow/temp
├── angular2@2.0.0-beta.3 
├── UNMET PEER DEPENDENCY es6-promise@^3.0.2
├── UNMET PEER DEPENDENCY es6-shim@^0.33.3
├── UNMET PEER DEPENDENCY reflect-metadata@0.1.2
├── UNMET PEER DEPENDENCY rxjs@5.0.0-beta.0
└── UNMET PEER DEPENDENCY zone.js@0.5.11

npm WARN angular2@2.0.0-beta.3 requires a peer of es6-promise@^3.0.2 but none was installed.
npm WARN angular2@2.0.0-beta.3 requires a peer of es6-shim@^0.33.3 but none was installed.
npm WARN angular2@2.0.0-beta.3 requires a peer of reflect-metadata@0.1.2 but none was installed.
npm WARN angular2@2.0.0-beta.3 requires a peer of rxjs@5.0.0-beta.0 but none was installed.
npm WARN angular2@2.0.0-beta.3 requires a peer of zone.js@0.5.11 but none was installed.
</code></pre>

<p>Is there a magic flag that I can pass to npm that will install the peer dependencies as well? I haven't been able to find one... It's tedious to manually copy and paste the peer dependencies and make sure I have the correct versions.</p>

<p>In other words, I'd rather not have to do:</p>

<pre><code>npm install --save angular2@2.0.0-beta.3 es6-promise@^3.0.2 es6-shim@^0.33.3 reflect-metadata@0.1.2 rxjs@5.0.0-beta.0 zone.js@0.5.11
</code></pre>

<p>What is the better way?</p>
