Merge branch 'add-terraform-optional-secret' into 'master'

Add optional terraform secret

This adds a single optional valuesFrom secret to enable deployment via the [Big Bang Terraform Launcher](https://repo1.dso.mil/platform-one/big-bang/terraform-modules/big-bang-terraform-launcher).

A working demo can be found here:  https://repo1.dso.mil/platform-one/quick-start/big-bang


/cc @runyontr @joshwolf


Add Big Bang Terraform Module secret injection

See merge request platform-one/big-bang/bigbang!383

base/helmrelease.yaml

@@ -26,6 +26,10 @@ spec:
     timeout: 10m
     cleanupOnFail: false
   valuesFrom:
+    # Optional secret injected with https://repo1.dso.mil/platform-one/big-bang/terraform-modules/big-bang-terraform-launcher
+    - kind: Secret
+      name: terraform
+      optional: true
     - kind: Secret
       name: common-bb
     - kind: ConfigMap