2.7.0

CHANGES:

• Fix use-after-free data race in CQE handlers (@avsm #124, reported #123 by @polytypic).

• Add socket bind and listen operations (@avsm #118).

• Update liburing to 2.7 (@avsm #118).

• Add Uring.Setup_flags module (@talex5 #122).

• Clean up configurator code and update primitives.h (@talex5 #121).

• Add mkdirat operation (@patricoferris #120).