Log Message:
devel/ruby-rspec-support: update to 3.7.1

### 3.7.1 / 2018-01-29
[Full Changelog](http://github.com/rspec/rspec-support/compare/v3.7.0...v3.7.1)

Bug Fixes:

* Fix source extraction logic so that it does not trigger a `SystemStackError`
  when processing deeply nested example groups. (Craig Bass, #343)

### 3.7.0 / 2017-05-04
[Full Changelog](http://github.com/rspec/rspec-support/compare/v3.6.0...v3.7.0)

Enhancements:

* Improve compatibility with `--enable-frozen-string-literal` option
  on Ruby 2.3+. (Pat Allan, #320)
* Add `Support.class_of` for extracting class of any object.
  (Yuji Nakayama, #325)

Bug Fixes:

* Fix recursive const support to not blow up when given buggy classes
  that raise odd errors from `#to_str`. (Myron Marston, #317)