Reduce image size

Dockerfile

@@ -1,14 +1,16 @@
 FROM ubuntu:16.04
 MAINTAINER Luke Childs <lukechilds123@gmail.com>
 
-RUN apt-get update
-RUN apt-get install -y curl unzip
-RUN curl -L https://github.com/vertcoin/vertcoin/releases/download/v0.11.1.0/vertcoin-v0.11.1.0-linux-64bit.zip --output prebuilt.zip
-RUN unzip prebuilt.zip
-RUN mv vertcoind /usr/local/bin
-
 ADD ./bin /usr/local/bin
-RUN chmod a+x /usr/local/bin/*
+
+RUN chmod a+x /usr/local/bin/* && \
+    apt-get update && \
+    apt-get install -y --no-install-recommends curl ca-certificates unzip && \
+    curl -L https://github.com/vertcoin/vertcoin/releases/download/v0.11.1.0/vertcoin-v0.11.1.0-linux-64bit.zip --output prebuilt.zip && \
+    unzip prebuilt.zip && \
+    mv vertcoind /usr/local/bin && \
+    apt-get purge -y curl ca-certificates unzip && \
+    apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
 VOLUME ["/data"]
 ENV HOME /data