imports should be sorted

[r-barnes]

Import should be sorted alphabetically and grouped, per the pep8 style guide (link).

Imports are always put at the top of the file, just after any module comments and docstrings, and before module globals and constants.

Imports should be grouped in the following order:

Standard library imports.
Related third party imports.
Local application/library specific imports.
You should put a blank line between each group of imports.

Problems include, but are not limited to this.

openjournals/joss-reviews#2276

[KevinShook]

Done!