FIX yarn test & selecting only core

[ndelangen]

Issue: -yarn test followed by only selecting core was broken.

This was broken by some internal change by jest or something.
By proving a absolute path this seems to work again.

Added the executed command for clarity.

[codecov]

Codecov Report

Merging #2219 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2219   +/-   ##
=======================================
  Coverage   21.44%   21.44%           
=======================================
  Files         263      263           
  Lines        5801     5801           
  Branches      689      692    +3     
=======================================
  Hits         1244     1244           
+ Misses       4024     4017    -7     
- Partials      533      540    +7

Impacted Files	Coverage Δ
app/vue/src/server/config/babel.js	0% <0%> (-100%)	⬇️
app/vue/src/server/babel_config.js	0% <0%> (-77.42%)	⬇️
lib/ui/src/modules/ui/containers/layout.js	12.5% <0%> (ø)	⬆️
lib/ui/src/modules/ui/components/menu_item.js	19.14% <0%> (ø)	⬆️
lib/ui/src/modules/ui/configs/init_panels.js	25% <0%> (ø)	⬆️
lib/ui/src/modules/ui/libs/hierarchy.js	48.8% <0%> (ø)	⬆️
lib/ui/src/modules/ui/components/layout/usplit.js	38.7% <0%> (ø)	⬆️
addons/storyshots/src/storybook-channel-mock.js	0% <0%> (ø)	⬆️
lib/ui/src/modules/api/actions/api.js	50.47% <0%> (ø)	⬆️
addons/knobs/src/components/types/Color.js	8.1% <0%> (ø)	⬆️
... and 11 more

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