Update Dockerfile

Dockerfile

@@ -2,10 +2,8 @@ FROM python:2-alpine
 MAINTAINER Michał "rysiek" Woźniak <rysiek@hackerspace.pl>
 
 # add Matomo log analytics
+RUN git clone --single-branch --branch 3.x-dev https://github.com/matomo-org/matomo-log-analytics.git /opt/matomo-log-analytics
 WORKDIR /opt/matomo-log-analytics
-RUN mkdir /opt/matomo-log-analytics && \
-    cd /opt/matomo-log-analytics && \
-    git clone --single-branch --branch 3.x-dev https://github.com/matomo-org/matomo-log-analytics.git
 
 ENTRYPOINT ["import_logs.py"]
 CMD ["--help"]