Update Dockerfile

Dockerfile

@@ -8,6 +8,8 @@ RUN openssl version
 RUN which openssl
 # install RVM, Ruby, and Bundler
 RUN \curl -L https://get.rvm.io | bash -s stable
+# rvm environment variable
+RUN /bin/bash -l -c "source /etc/profile.d/rvm.sh"
 RUN /bin/bash -l -c "rvm requirements"
 # replace ruby mirror url, accelerate install ruby
 RUN sed -i 's/rvm_remote_server_url2/#rvm_remote_server_url2/g' /usr/local/rvm/config/db