.travis.yml: fix windows install cmd for whatever-random-version3 it is

Signed-off-by: Stephen L Arnold <nerdboy@gentoo.org>

.travis.yml

@@ -15,19 +15,23 @@ matrix:
   fast_finish: true
   include:
     - os: osx
+      # osx is goofy, ``python`` is always py2, images mutate fast
       language: shell
       before_install:
-        - pip3 install --upgrade pip
+        - pip3 install --upgrade pip wheel
       install:
         - python3 setup.py install
       script:
         - pystache-test . ext/spec/specs
     - os: windows
+      # windows is even goofier, install path is different for python/python3
+      # but either way you get python3 and the cmd is always ``python``  o.O 
+      # (also versions mutuate like bacteria)
       language: shell
       before_install:
-        - choco install python
-        - python -m pip install --upgrade pip
-      env: PATH=/c/Python37:/c/Python37/Scripts:$PATH
+        - choco install python3 --params "/InstallDir:C:\\Python"
+        - python -m pip install --upgrade pip wheel
+      env: PATH="/c/Python:/c/Python/Scripts:$PATH"
       install:
         - python setup.py install
       script: