Add unit tests for export

Signed-off-by: Somtochi Onyekwere <somtochionyekwere@gmail.com>

cmd/flux/testdata/export/helm-release.yaml

@@ -0,0 +1,18 @@
+---
+apiVersion: helm.toolkit.fluxcd.io/v2beta1
+kind: HelmRelease
+metadata:
+  name: flux-system
+  namespace: {{ .fluxns }}
+spec:
+  chart:
+    spec:
+      chart: podinfo
+      reconcileStrategy: ChartVersion
+      sourceRef:
+        kind: HelmRepository
+        name: flux-systen
+        namespace: {{ .fluxns }}
+      version: '*'
+  interval: 5m0s
+