[REF] Refactor

app/db/library/__init__.py

@@ -1 +0,0 @@
-from .engine import engine

app/db/library/config.py

@@ -1,2 +0,0 @@
-engine_string = "sqlite://"
-echo = True

app/db/library/engine.py

@@ -1,4 +0,0 @@
-from sqlalchemy import create_engine
-from .config import engine_string, echo
-
-engine = create_engine(engine_string, echo=echo)