Tests frameworks are outdated

| Package | Used version | Latest version |
| --- | --- | --- |
| chai | 3.5.0 | 4.2.0 |
| chai-fs | 1.0.0 | 2.0.0 |
| mocha | 6.2.3 | 7.1.2 |
| sinon | 2.4.1 | 9.0.2 |