Replace Redis with PostgreSQL (usually already installed)

Author: Anze

.env.example

@@ -1,3 +1,8 @@
 BACKEND_URL=https://grafolean.com/api
 BOT_TOKEN=
 JOBS_REFRESH_INTERVAL=120
+DB_DIR=
+DB_HOST=
+DB_DATABASE=
+DB_USERNAME=
+DB_PASSWORD=

Pipfile

@@ -15,9 +15,9 @@ ansicolors = "*"
 easysnmp = {editable = true,git = "http://github.com/grafolean/easysnmp"}
 mathjspy = "*"
 numpy = "*"
-redis = "*"
 python-slugify = "*"
 grafoleancollector = "*"
+psycopg2-binary = "*"
 
 [requires]
 python_version = "3.6"