Bump versions

Dockerfile

@@ -1,23 +1,22 @@
-FROM debian:9-slim
+FROM debian:10-slim
 
 
-# Define image metadata
 LABEL maintainer="inf_sfb1288@lists.uni-bielefeld.de"
 
 
 ENV LANG=C.UTF-8
 
 
-# Install prerequisites
 RUN apt-get update \
  && apt-get install -y --no-install-recommends \
       imagemagick \
-      python3.5 \
-      zip \
- && rm -rf /var/lib/apt/lists/*
+      python3.7 \
+      zip
+
+
+RUN rm -rf /var/lib/apt/lists/*
 
 
-# Install merge_images
 COPY file_setup /usr/local/bin