Released v7.0.2

* **BACKWARD INCOMPATIBLE** Revert the change (released in v7.0.0) that
  required quoting in requirements files around specifiers containing
  environment markers. (:pull:`2841`)

* **BACKWARD INCOMPATIBLE** Revert the accidental introduction of support for
  options interleaved with requirements, version specifiers etc in
  ``requirements`` files. (:pull:`2841`)

* Expand ``~`` in the cache directory when caching wheels, fixes :issue:`2816`.

* Use ``python -m pip`` instead of ``pip`` when recommending an upgrade command
  to Windows users.