Add ability to specify source credentials if required

PROD-31387

Change-Id: I6425a37a3f179e13c5e6cb4184855169a0df63cf
diff --git a/jenkins/client/credential/source_git.yml b/jenkins/client/credential/source_git.yml
new file mode 100644
index 0000000..ec350f0
--- /dev/null
+++ b/jenkins/client/credential/source_git.yml
@@ -0,0 +1,10 @@
+parameters:
+  _param:
+    pipeline_library_source_credentials: source_git
+  jenkins:
+    client:
+      credential:
+        source_git:
+          desc: Credentials to source git repositories for pipelines
+          username: ${_param:source_git_username}
+          password: ${_param:source_git_password}