Ignore jekyll build output.

.gitignore

diff --git a/.gitignore b/.gitignore
index 24956f6..ef43625 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,6 @@
 /bazel-*
 # Ignore outputs generated during Bazel bootstrapping.
 /output/
+# Ignore jekyll build output.
+/production
+/.sass-cache