CompatHelper: bump compat for Oscar to 0.8, (keep existing compat)
This pull request changes the compat entry for the Oscar
package from ~0.7.0
to ~0.7.0, 0.8
.
This keeps the compat entries for earlier versions.
Note: I have not tested your package with this new compat entry. It is your responsibility to make sure that your package tests pass before you merge this pull request.