Adding version 13.0 of postgis + minor changes

Author: Haixuan Xavier Tao

repo/packages/P/postgis/0/config.json

@@ -41,8 +41,8 @@
         "version": {
           "description": "Postgres major version",
           "type": "string",
-          "enum": ["10.0-2.4"],
-          "default": "10.0-2.4"
+          "enum": ["10.0-2.4", "13.0"],
+          "default": "13.0"
         },
         "username": {
           "description": "Postgres user name.",

repo/packages/P/postgis/0/resource.json

@@ -1,8 +1,8 @@
 {
   "images": {
-    "icon-small": "https://en.wikipedia.org/wiki/File:PostGIS_logo.png#/media/File:PostGIS_logo.png",
-    "icon-medium": "https://en.wikipedia.org/wiki/File:PostGIS_logo.png#/media/File:PostGIS_logo.png",
-    "icon-large": "https://en.wikipedia.org/wiki/File:PostGIS_logo.png#/media/File:PostGIS_logo.png"
+    "icon-small": "https://upload.wikimedia.org/wikipedia/en/6/60/PostGIS_logo.png",
+    "icon-medium": "https://upload.wikimedia.org/wikipedia/en/6/60/PostGIS_logo.png",
+    "icon-large": "https://upload.wikimedia.org/wikipedia/en/6/60/PostGIS_logo.png"
   },
   "assets": {
     "container": {