updated travis yml

Author: lukasValentin

.travis.yml

@@ -9,7 +9,7 @@ addons:
     packages:
       - devscripts
 before_install:
-  - sudo apt-get install gdal python3-gdal
+  - sudo apt-get install python3-gdal
 install: 
   - pip install .
   - pip install -r requirements.txt