Breaks when a .rubocop directory exists

[joejuzl]

Rubocop errors when there is a directory named .rubocop

Expected behavior

Use the .rubocop.yml config

Actual behavior

Is a directory @ io_fillbuf - fd:7 .rubocop
/Users/joejuzl/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rubocop-0.42.0/lib/rubocop/options.rb:38:in `readlines'
/Users/joejuzl/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rubocop-0.42.0/lib/rubocop/options.rb:38:in `args_from_file'
/Users/joejuzl/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rubocop-0.42.0/lib/rubocop/options.rb:19:in `parse'
/Users/joejuzl/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rubocop-0.42.0/lib/rubocop/cli.rb:24:in `run'
/Users/joejuzl/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rubocop-0.42.0/bin/rubocop:14:in `block in <top (required)>'
/Users/joejuzl/.rbenv/versions/2.2.3/lib/ruby/2.2.0/benchmark.rb:303:in `realtime'
/Users/joejuzl/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/rubocop-0.42.0/bin/rubocop:13:in `<top (required)>'
/Users/joejuzl/.rbenv/versions/2.2.3/bin/rubocop:22:in `load'
/Users/joejuzl/.rbenv/versions/2.2.3/bin/rubocop:22:in `<main>'

Steps to reproduce the problem

Run rubocop in a directory with a sub-directory named .rubocop.

RuboCop version

$ rubocop -V
0.42.0