Docker updates

Dockerfile

@@ -23,6 +23,7 @@ RUN bundle config set --global no-cache 'true' && \
     bundle config set --global jobs `expr $(cat /proc/cpuinfo | grep -c 'cpu cores')` && \
     bundle config set --global retry 3
 
+
 FROM base as builder
 
 # packages required
@@ -38,7 +39,9 @@ COPY ./lib/travis/yml/version.rb ./lib/travis/yml/version.rb
 COPY Gemfile Gemfile.lock ./
 
 # Install gems
-RUN bundle install
+RUN bundle install && \
+    rm -rf /app/vendor/bundle/ruby/2.6.0/cache/* && \
+    for i in `find /app/vendor/ -name \*.o -o -name \*.c -o -name \*.h`; do rm -f $i; done
 
 
 FROM base
@@ -47,6 +50,7 @@ LABEL maintainer Travis CI GmbH <[email protected]
 
 # Copy gems from builder
 COPY --from=builder /usr/local/bundle /usr/local/bundle
+COPY --from=builder /app/vendor ./vendor
 
 # Copy app files
 COPY . ./