Log Message:
math/py-pandas-datareader: Update to 0.7.0

Changes:
* Reintroduced support for Yahoo! price, dividends, and splits data
  for stocks and currency pairs.
* A new data connector for data provided by Alpha Vantage was
  introduced to obtain Foreign Exchange (FX) data
* A new data connector for data provided by Alpha Vantage was
  introduced to obtain historical time series data.
* A new data connector for data provided by Alpha Vantage was
  introduced to obtain sector performance data.
* A new data connector for data provided by Alpha Vantage was
  introduced to obtain real-time Batch Stock Quotes.
* Immediate deprecation of Google finance and Morningstar for
  historical price data, as these API endpoints are no longer
  supported by their respective providers. Alternate methods are
  welcome via pull requests, as PDR would like to restore these
  features.
* Removal of EDGAR, which was deprecated in v0.6.0.