upd travis config

- try fix rpy2 install via apt

Author: 7048730

.travis.yml

@@ -15,6 +15,7 @@ before_install:
   - sudo apt-get install -y python-gdal
   - export CPLUS_INCLUDE_PATH=/usr/include/gdal
   - export C_INCLUDE_PATH=/usr/include/gdal
+  - sudo apt-get install python-rpy2
 install:
   - pip install GDAL==$(gdal-config --version | awk -F'[.]' '{print $1"."$2}')
   - pip install -r requirements.txt