Add checksum for Vertcoin binaries

CHECKSUM

@@ -0,0 +1 @@
+18a27d8ed5bc8cf87be308d7e8ceca089c9dc2b4344a1e47ece113c1c0eb161c

Dockerfile

@@ -3,12 +3,14 @@ LABEL maintainer="Luke Childs <lukechilds123@gmail.com>"
 
 COPY ./bin /usr/local/bin
 COPY ./VERSION /tmp
+COPY ./CHECKSUM /tmp
 
 RUN VERSION=`cat /tmp/VERSION` && \
     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/$VERSION/vertcoin-$VERSION-linux-64bit.zip --output /tmp/prebuilt.zip && \
+    echo "$(cat /tmp/CHECKSUM)  /tmp/prebuilt.zip" | sha256sum -c && \
     unzip /tmp/prebuilt.zip -d /tmp && \
     mv /tmp/vertcoind /usr/local/bin && \
     apt-get purge -y curl ca-certificates unzip && \