try fix helm unittest issues

Author: fealebenpae

.evergreen-functions.yml

@@ -678,6 +678,8 @@ functions:
       params:
         shell: bash
         working_dir: src/github.com/mongodb/mongodb-kubernetes
+        add_to_path:
+          - ${workdir}/bin
         script: |
           source .generated/context.export.env
           make helm-tests