Update Dockerfile

2.7/Dockerfile

@@ -8,7 +8,8 @@ RUN apt-get update && apt-get install -y \
     wget
     
 RUN wget -q -O - http://apt.clarin-pl.eu/KEY.gpg | apt-key add - && \
-    echo 'deb https://apt.clarin-pl.eu/ /' > /etc/apt/sources.list.d/clarin.list
+    echo 'deb https://apt.clarin-pl.eu/ /' > /etc/apt/sources.list.d/clarin.list && \
+    apt-get update
     
 RUN pip install --upgrade pip
 ENV PIP_EXTRA_INDEX_URL=https://pypi.clarin-pl.eu