Update templates with version number

Author: mrmrs

src/templates/header.html

@@ -3,7 +3,7 @@
     <a href="/" class="dib f5 f4-ns fw6 mt0 mb1 link black-70 dim" title="Home">
       Tachyons
       <div class="dib">
-        <small class="nowrap f6 mt2 mt3-ns pr2 black-70 fw2">v4.0.0-beta.29</small>
+        <small class="nowrap f6 mt2 mt3-ns pr2 black-70 fw2">v4.0.0-beta.31</small>
       </div>
     </a>
   </div>

src/templates/index.html

@@ -33,9 +33,9 @@ <h1>Getting Started</h1>
             <p class="measure lh-copy">
               Copy the line of code below and paste it in the head of the html file(s) you want to include tachyons in.
             </p>
-<pre class="pre black-70" style="overflow: auto"><code class="code f6 dib pa2 bg-near-white" style="font-size: 14px;">&lt;link rel="stylesheet" href="https://npmcdn.com/tachyons@4.0.0-beta.29/css/tachyons.min.css"&gt;</code></pre>
+<pre class="pre black-70" style="overflow: auto"><code class="code f6 dib pa2 bg-near-white" style="font-size: 14px;">&lt;link rel="stylesheet" href="https://npmcdn.com/tachyons@4.0.0-beta.31/css/tachyons.min.css"&gt;</code></pre>
 <p class="mt4"><b>or</b> install via npm</p>
-<pre class="pre black-70" style="overflow: auto"><code class="code f6 dib pa2 bg-near-white" style="font-size: 14px;">npm install --save-dev tachyons@4.0.0-beta.29</code></pre>
+<pre class="pre black-70" style="overflow: auto"><code class="code f6 dib pa2 bg-near-white" style="font-size: 14px;">npm install --save-dev tachyons@4.0.0-beta.31</code></pre>
 <p class="mt4"><b>or</b> grab all the source files and build+develop locally</p>
 <pre class="pre black-70" style="overflow: auto"><code class="code f6 dib pa2 bg-near-white" style="font-size: 14px;">git clone git@github.com:tachyons-css/tachyons.git
 cd tachyons