update docker files

.dockerignore

@@ -0,0 +1 @@
+target/

runtime_dockerfile

@@ -8,9 +8,5 @@ ENV TERM=xterm
 
 RUN rustup show
 
-# Ensure clean build
-RUN cargo clean
-RUN rm -fr target/
-
 # Build the runtime
 RUN cargo test && cargo build --release

wasm_dockerfile

@@ -1,4 +1,4 @@
-FROM liuchong/rustup:1.37.0 AS builder
+FROM liuchong/rustup:1.41.1 AS builder
 LABEL description="Joystream wasm toolchain image"
 
 ENV TERM=xterm