Add cow-based tests

5 jobs for !17 with cowsay in 2 minutes and 51 seconds (queued for 27 seconds)
latest merge request
Name Stage Failure
failed
gruppen: [4, iComputerfreak/DerCompiler, 0] Run

[SUCCESS] lexer:uppercase-keywords.mj correct
[SUCCESS] lexer:wild-whitespaces.mj correct
----------------------------------------
Ran 24 tests, of which 8 failed.
A full report for each test can be found at ../../../mjtest/reports/29-10-21_22-47-46.failed
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
gruppen: [3, larsk21/compiler-minijava, 0] Run
[SUCCESS] lexer:unicode_whitespace.invalid.mj     correct
[SUCCESS] lexer:uppercase-keywords.mj correct
[SUCCESS] lexer:wild-whitespaces.mj correct
----------------------------------------
Ran 24 tests, of which 2 failed.
A full report for each test can be found at ../../../mjtest/reports/29-10-21_22-46-22.failed
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
gruppen: [2, compilerpraktikum/compiler, 0] Run

[SUCCESS] lexer:uppercase-keywords.mj correct
[SUCCESS] lexer:wild-whitespaces.mj correct
----------------------------------------
Ran 24 tests, of which 7 failed.
A full report for each test can be found at ../../../mjtest/reports/29-10-21_22-44-58.failed
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
gruppen: [1, Firmwehr/gentle, 1] Run
[SUCCESS] lexer:unicode_whitespace.invalid.mj     correct
[SUCCESS] lexer:uppercase-keywords.mj correct
[SUCCESS] lexer:wild-whitespaces.mj correct
----------------------------------------
Ran 24 tests, of which 1 failed.
A full report for each test can be found at ../../../mjtest/reports/29-10-21_22-43-17.failed
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1