Having it in %PATH% means that powershell users will accidentally
run 'cipd.ps1' when they should be running 'cipd.bat'; This would
cause them to get requests for input parameters (like the backend URL)
which they have no idea how to supply.

R=agable@chromium.org, nodir@chromium.org, vadimsh@google.com

Bug: 1073529
Change-Id: I62a3bd9e00229a2047293dba1ba480d28f77bf63
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2161645Reviewed-by: Edward Lesmes <ehmaldonado@chromium.org>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>
Auto-Submit: Robbie Iannucci <iannucci@chromium.org>