Don't specify the version of libgeos in travis configs

WeatherGod · nbambruz · commit c0472e7cc6eb · 2017-10-19T08:21:00.000-06:00
diff --git a/.travis.yml b/.travis.yml
@@ -12,7 +12,7 @@ env:
 addons:
   apt:
     packages:
-      - libgeos-3.3.8   
+      - libgeos
       # matplotlib requirements
       - libpng12-dev
       - libfreetype6-dev
