Change Dockerfile to use non-root user

Signed-off-by: Nicko Guyer <nicko.guyer@kaleido.io>

Dockerfile

@@ -1,12 +1,12 @@
 FROM golang:1.19-buster AS builder
 WORKDIR /ethconnect
 RUN apt-get update -y \
- && apt-get install -y build-essential git \
- && curl -Lo /usr/bin/solc https://github.com/ethereum/solidity/releases/download/v0.8.15/solc-static-linux \
- && chmod 755 /usr/bin/solc
+    && apt-get install -y build-essential git \
+    && curl -Lo /usr/bin/solc https://github.com/ethereum/solidity/releases/download/v0.8.15/solc-static-linux \
+    && chmod 755 /usr/bin/solc
 ADD go.mod go.sum ./
 RUN grep -v ethbinding go.mod > go.mod.new \
- && cp go.mod.new go.mod
+    && cp go.mod.new go.mod
 RUN go get github.com/kaleido-io/ethbinding
 RUN go mod download
 ADD . .
@@ -27,4 +27,6 @@ RUN apt-get update \
     && ln -s /ethconnect/ethconnect /usr/bin/ethconnect
 
 RUN mkdir abis
+USER 1001
+
 ENTRYPOINT [ "./start.sh" ]