reproducer for #844
reproducer for #844

Add a pause right after the test removes the test directory and before
the redis worker is killed to increase the chances that the following
race happens:

* test delegates store.secure_unlinkto the redis worker
* test completes and remove /tmp/securedrop
* the redis worker evaluates store.secure_unlink and imports gnupg
* gnupg creates /tmp/securedrop/key
* the teardown function fails to verify the /tmp/securedrop has been removed

https://github.com/freedomofpress/securedrop/issues/844

conorsch/securedrop,conorsch/securedrop,micahflee/securedrop,micahflee/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,garrettr/securedrop,heartsucker/securedrop,garrettr/securedrop,ehartsuyker/securedrop,micahflee/securedrop,heartsucker/securedrop,micahflee/securedrop,ehartsuyker/securedrop,conorsch/securedrop,garrettr/securedrop,conorsch/securedrop,heartsucker/securedrop,ehartsuyker/securedrop,garrettr/securedrop,conorsch/securedrop,heartsucker/securedrop,heartsucker/securedrop,ehartsuyker/securedrop