[CI] move hadolint exceptions in specific config file

.drone.yml

@@ -17,7 +17,7 @@ steps:
 - name: docker lint
   image: hadolint/hadolint
   commands:
-  - hadolint --ignore DL3013 Dockerfile  # ignore pinning version in pip
+  - hadolint Dockerfile  # ignore pinning version in pip
 
 - name: w3c validator
   image: validator/validator:latest

.hadolint.yaml

@@ -0,0 +1,2 @@
+ignored:
+- DL3013