Modified names of variables to make code more understandable

Merge branch 'hschovanec-web-service-poc' of https://github.com/hschovanec-usgs/geomag-algorithms into hschovanec-usgs-hschovanec-web-service-poc

Done to prevent exceptions raised in python 3.6 environment.

Added a class to create error messages and wrapped parse, fetch,
and format_data in try/except statement to catch raised exceptions
and generate error pages.

Average Algorithm Unit Tests

Add Average Algorithm usage doc and Small tweak to Average Algorithm

Also, made changes based on PR revision requests.

Added base class for exceptions and continued work on parsing and
fetching methods.

Need to add more unit tests. Working on usgs/geomag-algorithms#162.

Multi observatory Averaging with updated that fixes #158

added a raise exception for more than 1 channel in configure

to geomag.py

averaged data

the interface friendlier

Use bytesio