Ruby on Rails

If there is a list devoted to ActiveRecord problems then I would appreciate a redirect.  In the absence of same I need some assistance with part of RoRs stack, namely ActiveRecord and the testing thereof.  I have a cli project which only uses AR-4.0 and whatever other stuff that gem pulls in. I am trialing the project witjh AR-4.1 and I am getting this error when I try to run my cucumber features:

      undefined method `assertions' for #<String:0x00000003ba4688> (NoMethodError)
      /home/byrnejb/Projects/Software/theHeart/code/hll_th_cadex_xfer/libexec/bundler/ruby/2.1.0/gems/rspec-expectations-3.0.3/lib/rspec/matchers.rb:902:in `method_missing'
      /home/byrnejb/Projects/Software/theHeart/code/hll_th_cadex_xfer/libexec/bundler/ruby/2.1.0/gems/minitest-5.4.0/lib/minitest/assertions.rb:126:in `assert'
      /usr/lib64/ruby/2.1.0/test/unit/assertions.rb:36:in `assert'
      /home/byrnejb/Projects/Software/theHeart/code/hll_th_cadex_xfer/features/step_definitions/hll_dbms_steps.rb:15:in `find_table_model_for'
      /home/byrnejb/Projects/Software/theHeart/code/hll_th_cadex_xfer/features/step_definitions/hll_dbms_steps.rb:30:in `block in <top (required)>'

I googled for this and found a couple of tangential references relating to a change in minitest. However, the fix appears to be somewhat dated and in any case this is not a full RoR stack so rspec-rails is not applicable.

https://stackoverflow.com/questions/16867707/rails-4-and-rspec-undefined-method-assertions-in-routing-spec

This problem is caused by a change in minitest 5.0 documented here:
# https://github.com/seattlerb/minitest/issues/286
is fixed by using: gem "rspec-rails", '~> 2.14.0.rc1'
in the gemfile.