(#62) Adjusted permissions for install in container

Author: s1hofmann

.travis.yml

@@ -23,6 +23,7 @@ before_install:
   - sudo apt-get -y -o Dpkg::Options::="--force-confnew" install docker-ce
   - docker pull s1hofmann/nut-ci:latest
   - docker run -it -d --name nut-ci --user $(id -u):$(id -g) -v ${PWD}:${PWD}:rw s1hofmann/nut-ci:latest bash
+  - docker exec --user 0 nut-ci chown -R $(id -u):$(id -g) /opt
 
 install: true