* Work around a segfault observed in SparsePage::Push()
* Revert "Work around a segfault observed in SparsePage::Push()"
This reverts commit 30934844d00908750a5442082eb4769b1489f6a9.
* Don't call vector::resize() inside OpenMP block
* Set GITHUB_PAT env var to fix R tests
* Use built-in GITHUB_TOKEN