[PATCH 3 of 6 v3] tests: use $PYTHON in #! so we always use the right Python

[Yuya Nishihara]

On Tue, 20 Jun 2017 10:10:38 -0400, Augie Fackler wrote:
> # HG changeset patch
> # User Augie Fackler <augie at google.com>
> # Date 1497551272 14400
> #      Thu Jun 15 14:27:52 2017 -0400
> # Node ID 395f5587885cfa3101c43dd76c4356e698aec472
> # Parent  b2f59445c55490bee0bc421d731a375691a7bc8a
> tests: use $PYTHON in #! so we always use the right Python

Queued these, many thanks!

CC Matt Harbison: can you check if this works on MSYS?