Merge pull request #27 from finnlabs/release/3.0

Release/3.0
Merge branch 'release/3.0' into dev (again)
Fix path of assets that should be precompiled

* Fix Array literal syntax
Remove unused :plugin option in asset helper calls
Merge pull request #28 from finnlabs/fix/remove-unused-asset-helper-option

Remove unused :plugin option in asset helper calls
update of version and changelog
Update require new stable OpenProject core 3.0.4
Merge branch 'release/3-0-2' into release/3.0
Merge branch 'release/3.0' into stable