Add -crt-static target-feature

Author: kpcyrd

Dockerfile

@@ -1,5 +1,7 @@
 # Start with a rust alpine image
 FROM rust:1-alpine3.11
+# This is important, see https://github.com/rust-lang/docker-rust/issues/85
+ENV RUSTFLAGS="-C target-feature=-crt-static"
 # if needed, install dependencies here
 #RUN apk add libseccomp-dev
 # set the workdir and copy the source into it