Increase code coverage

[benoitf]

it looks like we only have one unit test in the repository

$ yarn test                                                                                                                                                                                                                    ✓ src/authentication-service.spec.ts (1)
   ✓ An authentication token is converted to a session

 Test Files  1 passed (1)
      Tests  1 passed (1)
   Start at  13:48:08
   Duration  244ms (transform 81ms, setup 0ms, collect 103ms, tests 1ms, environment 0ms, prepare 43ms)
 % Coverage report from v8
---------------------------|---------|----------|---------|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------
File                       | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
---------------------------|---------|----------|---------|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------
All files                  |   18.07 |       20 |    2.63 |   18.07 |
 authentication-server.ts  |   25.19 |      100 |       0 |   25.19 | 31-73,75-111,113-127
 authentication-service.ts |   24.42 |      100 |    4.76 |   24.42 | 100-109,112-117,120-163,166-167,170-180,183-245,248-256,259-283,286-293,296-388,391-393,396-432,435-449,452-464,467-472,475-484,487-499,502-537,540-552,555-564
 configuration.ts          |       0 |        0 |       0 |       0 | 1-66
 extension.ts              |       0 |        0 |       0 |       0 | 1-290
 keychain.ts               |   53.12 |      100 |       0 |   53.12 | 30-42,45-52,55-63
 logger.ts                 |      50 |      100 |       0 |      50 | 27-34,37-38,41-42,45-56,59-69,72-74
 podman-cli.ts             |       0 |        0 |       0 |       0 | 1-118
 util.ts                   |       0 |        0 |       0 |       0 | 1-33
---------------------------|---------|----------|---------|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------