actions broken in latest iteration

[cfenzo]

In the latest commit, the new createAction function calls the action in stead of returning a callable action-function.

PR on the way..

[cfenzo]

codesandbox with the bug here:
https://codesandbox.io/s/4w7omoq950

replace imported ./unistore2 with ./unistore to see the old (2.2.0) behaviour, change to ./unistore3 to see the fix in the PR.

[developit]

Just released the fix in 2.4.0!