Build environment fail with rspec

bundle exec rspec --color --require spec_helper spec --format progress
Array values in the parameter to `Gem.paths=` are deprecated.
Please use a String or nil.
An Array ({"GEM_PATH"=>["/home/ubuntu/lottery/vendor/bundle/ruby/2.2.0", "/home/ubuntu/.rvm/gems/ruby-2.2.1", "/home/ubuntu/.rvm/gems/ruby-2.2.1@global"]}) was passed in from bin/rake:3:in `load'

I just found this error
and don’t quite sure what to fix since I didn’t upgrade rails or ruby