Fix later_api.h is newer than installed later #268

	# Workflow derived from https://github.com/rstudio/shiny-workflows
	#
	# NOTE: This Shiny team GHA workflow is overkill for most R packages.
	# For most R packages it is better to use https://github.com/r-lib/actions
	on:
	push:
	pull_request:
	name: Package checks
	jobs:
	website:
	uses: rstudio/shiny-workflows/.github/workflows/website.yaml@v1
	routine:
	uses: rstudio/shiny-workflows/.github/workflows/routine.yaml@v1
	R-CMD-check:
	uses: rstudio/shiny-workflows/.github/workflows/R-CMD-check.yaml@v1
	cpp-version-mismatch:
	name: cpp-version-mismatch
	runs-on: ubuntu-latest
	env:
	GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
	steps:
	- name: Checkout GitHub repo
	uses: rstudio/shiny-workflows/.github/internal/checkout@v1

	- name: Install R, system dependencies, and package dependencies
	uses: rstudio/shiny-workflows/setup-r-package@v1
	with:
	needs: check
	extra-packages: \|
	any::remotes
	- name: Compile promises against the newest later
	run: \|
	print(packageVersion("later"))
	remotes::install_github("rstudio/promises", force = TRUE)
	shell: Rscript {0}
	- name: Downgrade later
	run: \|
	remotes::install_version('later', '1.3.1')
	shell: Rscript {0}
	- name: See if dependent package (built against newer later ver) can still load
	run: \|
	print(packageVersion("later"))
	library(promises)
	shell: Rscript {0}

Provide feedback