Issue Ruby on Rails

[TomBowler]

Never setup Ruby via Plesk before in fact never had them on the same server... Anyway, need Ruby 2.3.1 on my Centos 7 Server running Plesk. Followed the guide and installed etc... all seems good, but when I run the Bundle install it errors out on a few things (see below).

• Warning: the running version of Bundler (1.13.5) is older than the version that created the lockfile (1.15.1). We suggest you upgrade to the latest version of Bundler by running `gem install bundler`.
  • An error occurred while installing nio4r (2.1.0), and Bundler cannot continue.
  • Make sure that `gem install nio4r -v '2.1.0'` succeeds before bundling.

One this I tried was running a gem install on nio4r and it states Ruby must be > v2.2.2 which I set in Plesk to be 2.3.1.
I then SSH into the server run ruby -v and it returns ruby 2.0.0p648 (2015-12-16) [x86_64-linux]
Any ideas on why?
Thanks