Update Dockerfile

Dockerfile

@@ -15,17 +15,9 @@ ENV USER user
 # External scripts
 ADD . /home/user
 RUN chmod +x install_rustup.sh
-RUN chmod +x install_rust_nightly.sh
-RUN chmod +x install_fmt.sh
 
 # Install Rust & Cargo
 RUN ./install_rustup.sh
 
-# Install Rust nightly
-RUN ./install_rust_nightly.sh
-
-# Install rustfmt-nightly
-RUN ./install_fmt.sh
-
 # Now act as `user`
 USER user
\ No newline at end of file