Merge pull request #49 from seavor/polina

Polina
idk
Merge pull request #50 from seavor/jay

idk
establish connection to JCORE DB inside Slim backend
Merge pull request #51 from seavor/jay

establish connection to JCORE DB inside Slim backend
cleanup Slim application file
Merge pull request #52 from seavor/jay

cleanup Slim application file