Duck tape PowerhShell coding

Author: dahlia

appveyor.yml

@@ -27,10 +27,10 @@ install:
 - ps: >
     git -C $env:APPVEYOR_BUILD_FOLDER submodule update --init;
     (new-object net.webclient).DownloadFile('https://bootstrap.pypa.io/get-pip.py', 'C:/get-pip.py');
-    $env:PYTHON\python.exe C:/get-pip.py;
-    $env:PYTHON\Scripts\pip.exe --version;
-    $env:PYTHON\Scripts\pip.exe install wheel;
-    $env:PYTHON\Scripts\pip.exe install -e .
+    "$env:PYTHON"\python.exe C:/get-pip.py;
+    "$env:PYTHON"\Scripts\pip.exe --version;
+    "$env:PYTHON"\Scripts\pip.exe install wheel;
+    "$env:PYTHON"\Scripts\pip.exe install -e .
 build: false
 test_script:
 - "dir \"C:\\Program Files (x86)\""