capture_output and text args are not available in Python3.6.

Bug: 1290210
Change-Id: Id3c70ad456c5ca56df9935d64229f599d7aae4b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3406721
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: David Munro <davidmunro@google.com>
Commit-Queue: David Munro <davidmunro@google.com>