rake raven:test does not work if environments are specified in config

[glebtv]

Example:

Raven.configure do |config|
  config.dsn = ...
  config.environments = %w(production staging)
end

rake raven:test 
divided by 0 excluded from capture: Not configured to send/capture in environment 'staging'

This seems to be due to .pop here:
https://github.com/getsentry/raven-ruby/blob/master/lib/raven/cli.rb#L21
It mutates config.environments so it no longer includes the environment we are sending for