add git pull

Author: bourgeoa

test/surface/docker/web-access-control/Dockerfile

@@ -1,5 +1,6 @@
 FROM solidtestsuite/web-access-control-tests
 # RUN git fetch origin
 RUN git fetch https://github.com/solid-contrib/web-access-control-tests.git
+RUN git pull
 RUN git checkout patchAppendNewDocument
 RUN git pull