en_US.UTF-8 locale by default

Dockerfile

@@ -6,7 +6,13 @@ MAINTAINER Michał "rysiek" Woźniak <rysiek@occrp.org>
 #
 
 # environment
-ENV DEBIAN_FRONTEND=noninteractive 
+ENV DEBIAN_FRONTEND=noninteractive
+
+# just in case some tool needs UTF-8 support
+ENV LANG en_US.UTF-8
+ENV LANGUAGE en_US:en
+ENV LC_ALL en_US.UTF-8
+RUN locale-gen en_US.UTF-8
 
 # we might need to install some packages, but doing this in the entrypoint doesn't make any sense
 ARG INSTALL_PACKAGES=
@@ -17,4 +23,4 @@ RUN if [ "$INSTALL_PACKAGES" != "" ]; then \
         rm -rf /var/lib/apt/lists/* ; \
     fi
 
-VOLUME /output
\ No newline at end of file
+VOLUME /output