Enhancement: Add time reporting for make.py

[pushfoo]

What to add?

Add basic time elapsed output for each commands in ./make.py

Why?

1. Make it easier for new contributors to report performance
2. Remove cross-platform ambiguities

Current Behavior

build succeeded, 5 warnings.

The HTML pages are in build/html.
>> Command finished: sphinx-build --jobs auto -b html -d build/doctrees doc build/html 


Build finished. The HTML pages are in /home/name/Projects/arcade/build/html.

Potential Desired Behavior

build succeeded, 5 warnings.

The HTML pages are in build/html.
>> Command finished (9m 56s): sphinx-build --jobs auto -b html -d build/doctrees doc build/html 


Build finished. The HTML pages are in /home/name/Projects/arcade/build/html.