GitLab::Projects: Add project_transfer method

GitLab/Projects.pm

@@ -362,6 +362,17 @@ my $requests = {
             id
         )],
     },
+
+    project_transfer => {
+        method      => 'PUT',
+        path        => '/projects/<id>/transfer',
+        required    => [qw(
+            namespace
+        )],
+        encode      => [qw(
+            namespace
+        )],
+    },
 };
 
 sub import {