Confllicting ruby version requirements?

[coolandsmartrr]

There seems to be different versions of Ruby specified in this project.

In Gemfile:

ruby '2.5.5'

In .ruby-version:

ruby-2.5.1

Questions:

1. Which version should one use when running on their machine?
2. Should this project change the version describe in one of these files?

[rajasegar]

I think we should follow Gemfile
looks like some omission from my side
https://andycroll.com/ruby/read-ruby-version-in-your-gemfile/