martelsans: Update fsSelection values

ofl/martelsans/DESCRIPTION.en_us.html

@@ -12,3 +12,6 @@ The Latin character set is an original design. Both character sets are the work
 The Martel Sans project is led by Dan Reynolds, a type designer based in Berlin, Germany. 
 To contribute, see <a href="https://github.com/typeoff/martel_sans">github.com/typeoff/martel_sans</a>
 </p>
+<p>
+<b>Updated November 2015:</b> Internal metadata corrected.
+</p>

ofl/martelsans/METADATA.json

@@ -1,6 +1,6 @@
 {
   "name": "Martel Sans",
-  "designer": "Dan Reynolds",
+  "designer": "Dan Reynolds and Mathieu Réguer",
   "license": "OFL",
   "visibility": "Sandbox",
   "category": "Sans Serif",