refactor: refactor Dockerfile

Author: trueChazza

Dockerfile

@@ -3,9 +3,8 @@ FROM elixir:1.13
 RUN apt-get update && \
     apt-get install -y inotify-tools postgresql-client
 
-RUN mkdir /app
-COPY . /app
 WORKDIR /app
+COPY . /app
 
 ARG MIX_ENV="dev"
 ARG SECRET_KEY_BASE=""