More client unit tests & python unittest CI support w/ coverage report

[cchudant]

Description

More python unit tests

Name                          Stmts   Miss  Cover
-------------------------------------------------
blindai/__init__.py               0      0   100%
blindai/client.py               207     16    92%
blindai/dcap_attestation.py      73      5    93%
blindai/utils/__init__.py         0      0   100%
blindai/utils/errors.py          24     15    38%
blindai/utils/utils.py           32      3    91%
blindai/version.py                1      0   100%
-------------------------------------------------
TOTAL                           337     39    88%

(we should put coverage reports in the CI by the way)

Related Issue

None

Type of change

• [ ] This change requires a documentation update
• [x] This change affects the client
• [ ] This change affects the server
• [ ] This change affects the API
• [ ] This change only concerns the documentation

How Has This Been Tested?

N/A

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] My changes generate no new warnings
• [x] I have updated the documentation according to my changes