From 162b2441a8e8d84d8b4a681f25a32c5e705a6a65 Mon Sep 17 00:00:00 2001
From: Jordan Suchow <suchow@post.harvard.edu>
Date: Tue, 16 Aug 2016 23:35:14 -0400
Subject: [PATCH] Ensure a clean commit history

---
 Dangerfile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Dangerfile b/Dangerfile
index 53130cbaa..d09625469 100644
--- a/Dangerfile
+++ b/Dangerfile
@@ -1,2 +1,7 @@
 # Look for prose issues
 prose.lint_files
+
+# Ensure a clean commits history
+if git.commits.any? { |c| c.message =~ /^Merge branch/ }
+  fail('Please rebase to get rid of the merge commits in this PR')
+end