Pandas-ta

New:
* Include External Custom Indicators independent of builtin Pandas TA indicators.
* Jurik MA indicator included.

Updated:
* Google Colab **numpy** dependencies differences fix 285.
* TA Lib integration improvements.
* Enable/Disable TA Lib functions with talib argument. See indicator help().

Other:
* Misc. Refactoring.

Updated:
* Added **tos_stdevall** indicator
* Volume Profile **vp** Improvements

Other:
* Minor Refactoring
* Accepts a string for a single column when using 'col_names'

Updated:
* Fixed **psar** calculations
* Add **bbands** percent to **bbands**
* Added **dm**
* Added **xsignals** (BETA)

Updated:
* Bug fix for swapped upper and lower **bbands**
* New columns names for **amat** and **zscore**

Added:
* Users get TA Lib speeds if TA Lib is installed. (Most but not _all_ TA Lib indicators are included)

Other:
* Updated Notebooks
* Refactoring