Add jest tests to CI pipeline

[yatki]

Expected behavior

• [x] We need to run Jest tests alongside with mocha tests on Jenkins.
• [x] We should be able to run jest tests and mocha test suites at once with a top level command. Eg "npm test:unit": "run-p mocha:unit jest:unit"
• [x] Merge code coverage from both test runners.

Actual behavior

• Jenkinsfile is not configured to run Jest tests.
• We don't have a top level command to run test runners.

Steps to reproduce

Which version(s) does this affect? (Environment, OS, etc...)

1.6.0

[michielmulders]

Added --passWithNotests flag for jest:integration and jest:functional as the absence of tests makes Jenkins fail.

[michielmulders]

Jest added to Jenkins script and create a command that executes all tests for a certain type e.g. unit. However, using this command, the success/failure of the separate commands are lost between all the logs as they execute in parallel.

Todo @yatki

• Work on merging code coverage
• Possibly move the .code-coverage from root to test as the coverage from Mocha is located under /test. If doing so, check Jenkins script cleanup function (post step) for the Jest steps as paths need to be changed.

We can safely remove the --passWithNotests flag in package.json script for running Jest tests whenever we have tests for each type (functional and integration).