Log Message:
math/py-pandas-datareader: Update to 0.6.0

Notable changes:
- Immediate deprecation of Yahoo!, Google Options and Quotes and
  EDGAR. The end points behind these APIs have radically changed and
  the existing readers require complete rewrites. In the case of most
  Yahoo! data the endpoints have been removed. PDR would like to
  restore these features, and pull requests are welcome.
- A new connector for Tiingo was introduced. Tiingo provides
  historical end-of-day data for a large set of equities, ETFs and
  mutual funds. Free registration is required to get an API key.
- A new connector for Robinhood was introduced. This provides up to 1
  year of historical end-of-day data. It also provides near real-time
  quotes.
- A new connector for Morningstar Open, High, Low, Close and Volume
  was introduced.
- A new connector for IEX daily price data was introduced.
- A new connector for IEX the majority of the IEX API was introduced.
- A new data connector for stock index data provided by Stooq was
  introduced.
- A new data connector for data provided by the Bank of Canada was
  introduced.