Fixed no such file or directory error in decoratormanager.js Test File (

#837)

* Fixed no such file error

Signed-off-by: Subhajit Ghosh <subhajitstd07@gmail.com>

* Join the  directory and path of the file using path.join

Signed-off-by: Subhajit Ghosh <subhajitstd07@gmail.com>

* Added comma seperated list arguement into path.join function

Signed-off-by: Subhajit Ghosh <subhajitstd07@gmail.com>

* Update packages/concerto-core/test/decoratormanager.js

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Signed-off-by: Subhajit Ghosh <subhajitstd07@gmail.com>
Co-authored-by: Matt Roberts <7544022+mttrbrts@users.noreply.github.com>