[ofiwg] libfabric v1.7.0rc1

[Hefty, Sean]

I've published RC1 for v1.7.0:

https://github.com/ofiwg/libfabric/releases/tag/v1.7.0rc1

I'm aware of a couple of outstanding issues that may require creating an rc2 once fixes are available.  Please report any found bugs to the mailing list or github issues.

Provider maintainers, please look over the NEWS.md file to see if I missed any updates.  Provider specific man pages should also be updated as needed.

Thanks,
- Sean