Release v3.3.1

• fab1b33 Fix for #83: Add the possibility to mount files from secret
• 331e258 Fix for #82: Wrong mount name used
• 3cb19e7 Fix for #84: Do not set storageClassName if not set in values.yml
• ddc147f Fix: Fix missing word in README.md
• 956caf3 Upd #63: Gracefully scaledown Postfix