Adding CryptoCompare to coins suite

Release adds CryptoCompare API to coins support. This should provide a deeper and more reliable quote feature than HitBTC

• Adds coins.get_quote_cc() to generate coin quote from CC
• Adds coins.get_ohlc_cc() to generate OHLC data from CC
• Added to_yahoo argument to coins.*_quote_*() functions: reformats headers to look like yahoo finance ones
• Added find_uniques() for header-checking tests
• Added pytest-xdist and python setup.py fast command for faster dev test loops
• Updated tests to be multi-thread friendly
• Touched up rh_news tests to be less sensitive to schema updates