Put facter development dependence in template as well.
diff --git a/templates/grpc.gemspec.template b/templates/grpc.gemspec.template
index 701e1c7..6f8d1fb 100644
--- a/templates/grpc.gemspec.template
+++ b/templates/grpc.gemspec.template
@@ -37,6 +37,7 @@
     s.add_dependency 'googleauth',      '~> 0.5.1'
 
     s.add_development_dependency 'bundler',            '~> 1.9'
+    s.add_development_dependency 'facter',             '~> 2.4'
     s.add_development_dependency 'logging',            '~> 2.0'
     s.add_development_dependency 'simplecov',          '~> 0.9'
     s.add_development_dependency 'rake',               '~> 10.4'