Update Dangerfile to be less noisy, close Instagram#792

Summary:
Issue fixed: Instagram#792

- [ ] All tests pass. Demo project builds and runs.
- [ ] I added tests, an experiment, or detailed why my change isn't tested.
- [ ] I added an entry to the `CHANGELOG.md` for any breaking changes, enhancements, or bug fixes.
- [ ] I have reviewed the [contributing guide](https://github.com/Instagram/IGListKit/blob/master/.github/CONTRIBUTING.md)
Closes Instagram#795

Differential Revision: D5132076

Pulled By: rnystrom

fbshipit-source-id: 7d68f842e0244d6c6184982ee434dc4da22cc7c6

Dangerfile

@@ -9,7 +9,7 @@ warn("Big PR") if git.lines_of_code > 500
 
 # Changelog entries are required for changes to library files.
 no_changelog_entry = !git.modified_files.include?("CHANGELOG.md")
-if has_source_changes && no_changelog_entry && not_declared_trivial
+if has_source_changes && no_changelog_entry && not_declared_trivial && git.lines_of_code > 10
   fail("Any source code changes should have an entry in CHANGELOG.md.")
 end