Aguaclara

Fixed units on max value of 1 in gamma_humic_acid_to_coag (272)

Release updated to 0.2.2, fixed pint version (273)

Getting Travis to work

- updated all dependencies to use the latest version of Matplotlib
- removed support for Python 3.5 because most users have migrated to use of it in Google Colab, which supports Python 3.6

- The only change in this release is the update in pipfile for the Matplotlib version to the most recent one rather than implementing an older version of it to fix errors thrown when running !pip install aguaclara in Google Colab.

* The `core.utility.list_handler()` function decorator has been widely applied to functions in the `research` and `core` subpackages, allowing them to accept and output either scalar or array quantities.
* The `u.wraps()` unit wrapper, which was causing poor programming practice and many bugs, has been removed from the entire package.
* Documentation and naming of functions in `core.physchem` have been improved and standardized. Deprecation warnings have been included for functions and parameters that are changing names.

The Gran function in `environmental_processes_analysis.py` now correctly passes `header=None` to `pandas.read_csv()` instead of `header=-1`.