Commits
Wes McKinney authored 0e0da74c540
ARROW-1460: [C++] Pin clang-format at LLVM 4.0 Author: Wes McKinney <wes.mckinney@twosigma.com> Closes #1037 from wesm/ARROW-1460 and squashes the following commits: 2cfc3532 [Wes McKinney] Use clang-format-4.0