Not making correct call for v3 dataset CBOE/VXEEM

[Victory]

see: https://www.quandl.com/data/CBOE/VXEEM-Emerging-Markets-ETF-Volatility-Index

I have the following failing test in my branch which i will push and have a pull request with the fix

  1) quandl contains last_uri_call has correct api call for v3:

  AssertionError: "api/v3/datasets/CBOE/VXEEM/" == "api/v3/datasets/CBOE/VXEEM"
  + expected - actual

  +"api/v3/datasets/CBOE/VXEEM.json"
  -"api/v3/datasets/CBOE/VXEEM/"