fix doc version switch

doc/.static/version_switch.js

@@ -75,10 +75,13 @@
     if (vlabel == 'theano') {
       vlabel = 'release';
     }
+    else if (vlabel != "dev") {
+        vlabel = '';
+    }
     var vswitch = ['<div class="rst-versions-up" data-toggle="rst-versions" role="note" aria-label="versions" align=center>'];
     vswitch.push('<span class="rst-current-version" data-toggle="rst-current-version">');
     vswitch.push(vlabel);
-    vswitch.push('<span class="fa fa-caret-down"></span>');
+    vswitch.push(' <span class="fa fa-caret-down"></span>');
     vswitch.push('</span>');
     vswitch.push('</div>');
     return vswitch.join('');