Update packages.json & build-matrix.html

docs/build-matrix.html

@@ -1009,7 +1009,7 @@ feel free to submit a pull request.
 
 <tr>
  <th class="row" title=""> gsl   </th>
- <td>2.3 </td>
+ <td>2.5 </td>
       <td class="supported">&#x2713;</td>
       <td class="supported">&#x2713;</td>
       <td class="supported">&#x2713;</td>

docs/packages.json

@@ -96,7 +96,7 @@
     "googletest": {"version": "1.7.0", "website": "https://github.com/google/googletest", "description": "Google Test"},
     "gpgme": {"version": "1.12.0", "website": "https://www.gnupg.org/related_software/gpgme/", "description": "gpgme"},
     "graphicsmagick": {"version": "1.3.21", "website": "http://www.graphicsmagick.org/", "description": "GraphicsMagick"},
-    "gsl": {"version": "2.3", "website": "https://www.gnu.org/software/gsl/", "description": "GSL"},
+    "gsl": {"version": "2.5", "website": "https://www.gnu.org/software/gsl/", "description": "GSL"},
     "gsoap": {"version": "2.8.84", "website": "https://www.genivia.com/dev.html", "description": "gSOAP"},
     "gst-libav": {"version": "1.16.0", "website": "https://gstreamer.freedesktop.org/modules/gst-libav.html", "description": ""},
     "gst-plugins-bad": {"version": "1.16.0", "website": "https://gstreamer.freedesktop.org/modules/gst-plugins-bad.html", "description": ""},