Set channel priority to strict.

Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>

.gitlab-ci.yml

@@ -53,8 +53,8 @@ test_sensormapgeo_install:
     - source activate sensormapgeo_testinstall
 
     # resolve some requirements with conda
-    - conda install --yes -q -c conda-forge gdal libgdal
-    - conda install --yes -q -c conda-forge numpy pyresample pyqt scikit-image rasterio pyproj lxml geopandas ipython
+    - conda config --set channel_priority strict
+    - conda install --yes -q -c conda-forge numpy gdal pyresample pyqt scikit-image rasterio pyproj lxml geopandas ipython
 
     # run installer
     - python setup.py install