Add various vulnerability scanning configs (#69)

After recent package updates and other fixes[1][2][3][4], ignore remaining false
positives/things of less immediate concern.

[1] 37ff3d9
[2] 315596d
[3] e2ea148
[4] ef36d7b

Author: doshitan

template/{{app_name}}/.dockleconfig

@@ -0,0 +1,4 @@
+# This file is allows you to specify a list of files that is acceptable to Dockle
+# To allow multiple files, use a list of names.
+# https://github.com/goodwithtech/dockle#accept-suspicious-environment-variables--files--file-extensions
+DOCKLE_ACCEPT_FILES=omniauth.rb,rails/config/database.yml

template/{{app_name}}/.hadolint.yaml

@@ -0,0 +1,7 @@
+# List of settings and ignore or safelist findings for the hadolint scanner
+
+# For more information on any settings you can specify, see the actions' documentation here
+# https://github.com/hadolint/hadolint#configure
+failure-threshold: warning
+ignored:
+  - DL3008 # ideally we might just pin the docker image itself

template/{{app_name}}/trivy-secret.yaml

@@ -0,0 +1,4 @@
+allow-rules:
+  - id: jwt-token
+    description: Skip commented out/example JWT secret embedded in AWS SDK source code
+    path: .*/aws-sdk-ssooidc/client\.rb