use readYaml for reading context

Change-Id: I857cfdbcfe433fb9406795468f0d82322b8913e7
diff --git a/generate-cookiecutter-products.groovy b/generate-cookiecutter-products.groovy
index faaf704..8581089 100644
--- a/generate-cookiecutter-products.groovy
+++ b/generate-cookiecutter-products.groovy
@@ -28,7 +28,7 @@
         def modelEnv = "${env.WORKSPACE}/model"
 
         try {
-            def templateContext = python.loadJson(COOKIECUTTER_TEMPLATE_CONTEXT)
+            def templateContext = readYaml text: COOKIECUTTER_TEMPLATE_CONTEXT
             def templateDir = "${templateEnv}/template/dir"
             def templateOutputDir = "${env.WORKSPACE}/template"
             def cutterEnv = "${env.WORKSPACE}/cutter"