Deploy BE on railway

[bhtibrewal]

Issue Description

Expected Behavior

NOTE: Dependent on this PR #83

Steps

1. Deploy a mysql db. Goto https://railway.app/new and choose "Provision MySQL."
   
2. Deploy skill-tree-backend, Click "New" and choose "Github Repo" and than "Configure Github App" and add "skill-tree-backend"

3. Go "skill-tree-backend" Settings > General and add "/skill-tree" under `Root Directory`

4. Go "skill-tree-backend" Variables and add the following variables

MYSQL_DB_PASSWORD=${{MySQL.MYSQL_ROOT_PASSWORD}}
DB_DDL_POLICY=update
DB_NAME=${{MySQL.MYSQL_DATABASE}}
MYSQL_DB_USERNAME=root
MYSQL_HOST=${{MySQL.MYSQLHOST}}
RDS_PUBLIC_KEY="-----BEGIN PUBLIC KEY-----
                xxxxxxxxxxxxxxxxx
                -----END PUBLIC KEY-----"
MYSQL_PORT=${{MySQL.MYSQLPORT}}

[bhtibrewal]

DONE so closing