test: unit tests for `ecs.py`

[manmartgarc]

This PR adds basic unit tests for the ecs.py module.

Additions:

• Unit tests for the ecs.py module.

Editions:

• Refactor the cpu and memory attributes of the ECSTask class to have better check guards for weird values/types.

[github-actions[bot]]

Coverage Report

File	Stmts	Miss	Cover	Missing
/opt/hostedtoolcache/Python/3.9.16/x64/lib/python3.9/site-packages/cloudtile
__init__.py	0	0	100%
__main__.py	0	80	32%	30, 34, 40, 44, 46, 49, 51, 58–59, 66–69, 71–74, 77–79, 82–87, 89–94, 96–98, 103, 105, 109–110, 116, 123–129, 148, 153–156, 160, 164, 168, 172–173, 177, 181, 185, 193–194, 198, 201–202, 207, 215, 220, 225, 252, 257–258, 262, 266, 277, 280, 287, 300–301, 305
converter.py	0	49	25%	33, 40, 44–46, 54–55, 58–59, 61, 63–66, 77–80, 82, 87, 90–91, 93–95, 97–98, 100–102, 122–124, 126, 128–130, 132–135, 137, 139–141, 143–145, 147
ecs.py	0	0	100%
geofile.py	0	0	100%
s3.py	0	0	100%
TOTAL	503	129	74%

Tests	Skipped	Failures	Errors	Time
75	0 :zzz:	0 :x:	0 :fire:	6.165s :stopwatch: