Add SELinux policy

If one tries to run hashr using Linux with enforced SELinux, there will be an access violation when it comes to the preprocessing.
This is due to incompatibility in SELinux contexts of /tmp and docker

AVC Events:
scontext=system_u:system_r:container_t:
tcontext=unconfined_u:object_r:user_tmp_t

General solutions (maybe there are more):
1. Custom SELinux policy
2. Change default preprocessing directory or provide flag to do so
3. Disable SELinux: Don't think this should be a general solution