CI: How to set UTF-8 in the server?

Hi,

I have the following error in my builds:

$ bundle install
/usr/local/lib/ruby/gems/2.3.0/gems/bundler-1.11.2/lib/bundler/dsl.rb:482:in 
`parse_line_number_from_description': invalid byte sequence in US-ASCII (ArgumentError)

This happens because I have a written accent in my *.gemspec file:

  s.author      = "Francesco Rodríguez"

I tried without it and the build succeeds. Is there anyway to set the right locale in the CI server?

Repository: https://gitlab.com/frodsan/envoker

Thanks!