Remove rvm global trick

Author: pirj

script/update_rubygems_and_install_bundler

@@ -10,7 +10,7 @@ if is_ruby_23_plus; then
   echo "Current bundler versions installed: `gem list | grep '^bundler ('`"
   gem uninstall -aIx bundler || echo "Warning error occured removing bundler via gem"
   rvm @global do gem uninstall -aIx bundler || echo "Warning error occured removing bundler via rvm"
-  yes | rvm @global do gem install bundler
+  yes | gem install --force bundler
   echo "Current bundler versions installed after 'gem install bundler': `gem list | grep '^bundler ('`"
   bundle binstubs bundler --force
 else