use lighter final ubuntu image for joystream-node

joystream-node.Dockerfile

@@ -19,7 +19,7 @@ RUN BUILD_DUMMY_WASM_BINARY=1 cargo clippy --release --all -- -D warnings && \
     cargo test --release --all && \
     cargo build --release
 
-FROM rust:1.52.1-slim-buster
+FROM ubuntu:21.04
 LABEL description="Joystream node"
 WORKDIR /joystream
 COPY --from=builder /joystream/target/release/joystream-node /joystream/node

setup.sh

@@ -17,6 +17,8 @@ elif [[ "$OSTYPE" == "darwin"* ]]; then
     brew update
     brew install coreutils gnu-tar jq curl
     echo "It is recommended to setup Docker desktop from: https://www.docker.com/products/docker-desktop"
+    echo "It is also recommended to install qemu emulators with following command:"
+    echo "docker run --privileged --rm tonistiigi/binfmt --install all"
 fi
 
 # If OS is supported will install build tools for rust and substrate.