Cut more ties to k8sdeps

Add tests for all the plugins.

plugin/builtin/secretgenerator/SecretGenerator.go

@@ -31,8 +31,5 @@ func (p *plugin) Config(
 }
 
 func (p *plugin) Generate() (resmap.ResMap, error) {
-	argsList := make([]types.SecretArgs, 1)
-	argsList[0] = p.SecretArgs
-	return p.rf.NewResMapFromSecretArgs(
-		p.ldr, &p.GeneratorOptions, argsList)
+	return p.rf.FromSecretArgs(p.ldr, &p.GeneratorOptions, p.SecretArgs)
 }