modify dockerfile to fix build issues

Dockerfile

@@ -1,4 +1,4 @@
-FROM phusion/passenger-full
+FROM phusion/passenger-full:2.5.1
 
 ARG PASSENGER_APP_ENV=production
 
@@ -9,7 +9,6 @@ ADD bonnie.conf /etc/nginx/sites-enabled/bonnie.conf
 
 COPY --chown=app:app . /home/app/bonnie
 
-RUN bash -lc "rvm install ruby-${RUBY_VERSION} && rvm --default use ruby-${RUBY_VERSION}"
 
 RUN rm -f /etc/service/nginx/down \
     && rm -f /etc/nginx/sites-enabled/default \
@@ -20,6 +19,9 @@ RUN rm -f /etc/service/nginx/down \
     && apt-get install shared-mime-info -y
 
 RUN su - app -c "cd /home/app/bonnie \
+                 && rvm autolibs disable \
+                 && rvm install ruby-${RUBY_VERSION} \
+                 && rvm --default use ruby-${RUBY_VERSION} \
                  && curl -O https://s3.amazonaws.com/rds-downloads/rds-combined-ca-bundle.pem \
                  && gem install bundler -v 2.1.4 \
                  && bundle install \