Run tests in nvim as well as vim.

test/test

@@ -2,15 +2,22 @@
 
 VIM="/Applications/MacVim.app/Contents/MacOS/Vim -v"
 
+status=0
+
 # Execute the tests.
+for editor in "$VIM" nvim; do
+
   for testcase in test*.vim; do
-  $VIM -N -u NONE --cmd 'let g:gitgutter_async=0' -S $testcase -c 'quit!'
+    $editor -N -u NONE --cmd 'let g:gitgutter_async=0' -S $testcase -c 'quit!'
 
     git reset HEAD fixture.txt > /dev/null
     git checkout fixture.txt
   done
 
   # Verify the results.
+  echo "$editor:"
+  echo
+
   count_ok=0
   count_fail=0
 
@@ -33,6 +40,11 @@ echo
   echo "$((count_ok + count_fail)) tests"
   echo "$count_ok ok"
   echo "$count_fail failed"
+  echo
 
-exit $count_fail
+  status=$(($status + $count_fail))
+
+done
+
+exit $status