blinker, click, flask, itsdangerous, werkzeug: upgraded packages to upstream

Upgraded dev-python/werkzeug to version 0.15.5 on amd64
Upgraded dev-python/itsdangerous to version 0.24-r1 on amd64
Upgraded dev-python/blinker to version 1.4 on amd64
Upgraded dev-python/click to version 7.0 on amd64
Upgraded dev-python/flask to version 1.0.4 on amd64

Manually deleted files/ folder.

BUG=chromium:1049699
TEST=rebuild chroot, ran `sudo emerge flask` and `sudo emerge -cav flask` to
test package can be imported on demand.

Change-Id: Ib3f9bc800ac1578a655b1f46d35011c33daea195
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2042363
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Hirthanan Subenderan <hirthanan@google.com>
Tested-by: Hirthanan Subenderan <hirthanan@google.com>
20 files changed