release/7.7.0

We are pleased to announce the release of version 7.7.0
of the Cooperative Computing Tools from the University of Notre Dame,
including TaskVine, Work Queue, Makeflow, Parrot, Chirp, and other software.

Docs: https://cctools.readthedocs.io/
Download: http://ccl.cse.nd.edu/software/download
Forum: http://ccl.cse.nd.edu/community/forum

This is a feature release that primarily improves the scalability and performance of TaskVine:

Main Features:

• TaskVine workers now perform transfers asynchronously while communicating with manager, by @BarrySlyDelgado
• TaskVine Serverless function execution simplified and accelerated by @tphung3
• Improved integration of Parsl and TaskVine by @tphung3
• Improved scheduler performance in Work Queue and TaskVine by @colinthomas-z80
• Multiple improvements to reliability at scale with physics applications by @btovar
• Change to API for cancelling tasks: all tasks are now returned by vine_wait by @dthain
• Change to serverless resource management: functions consume library resources by @dthain
• Improved visualization by @JinZhou5042
• New environment.yml for development dependencies by @thieber22

Full Changelog: nightly...release/7.7.0