Add "PostRendererArgs" option to be passed to helm (#1133)

* Add "PostRendererArgs" option to be passed to helm

This allows using PowerShell scripts on Windows as Post Renderer.

Signed-off-by: Maarten Boekhold <maarten.boekhold@finastra.com>

test/integration/test-cases/postrender/output/diff-result

@@ -11,7 +11,7 @@ helmfile-tests, cm2, ConfigMap (v1) has been added:
 + apiVersion: v1
 + kind: ConfigMap
 + data:
-+   two: TWO
++   name: cm2 
 + metadata:
 +   name: cm2
 helmfile-tests, foo-1, ConfigMap (v1) has been added:
@@ -46,7 +46,7 @@ helmfile-tests, cm1, ConfigMap (v1) has been added:
 + apiVersion: v1
 + kind: ConfigMap
 + data:
-+   one: ONE
++   name: cm1 
 + metadata:
 +   name: cm1
 

test/integration/test-cases/postrender/output/diff-result-live

@@ -11,7 +11,7 @@ helmfile-tests, cm2, ConfigMap (v1) has been added:
 + apiVersion: v1
 + kind: ConfigMap
 + data:
-+   two: TWO
++   name: cm2 
 + metadata:
 +   name: cm2
 helmfile-tests, foo-1, ConfigMap (v1) has been added:
@@ -44,7 +44,7 @@ helmfile-tests, cm1, ConfigMap (v1) has been added:
 + apiVersion: v1
 + kind: ConfigMap
 + data:
-+   one: ONE
++   name: cm1 
 + metadata:
 +   name: cm1
 Comparing release=foo, chart=../../../charts/raw

test/integration/test-cases/postrender/output/template-result

@@ -14,7 +14,7 @@ data:
 apiVersion: v1
 kind: ConfigMap
 data:
-  two: TWO
+  name: cm2 
 metadata:
   name: cm2
 
@@ -32,7 +32,7 @@ data:
 apiVersion: v1
 kind: ConfigMap
 data:
-  one: ONE
+  name: cm1 
 metadata:
   name: cm1
 

test/integration/test-cases/postrender/output/template-result-live

@@ -15,7 +15,7 @@ data:
 apiVersion: v1
 kind: ConfigMap
 data:
-  two: TWO
+  name: cm2 
 metadata:
   name: cm2
 
@@ -33,7 +33,7 @@ data:
 apiVersion: v1
 kind: ConfigMap
 data:
-  one: ONE
+  name: cm1 
 metadata:
   name: cm1