Allow running scripts using msys2/mingw/git bash (#1954)

Signed-off-by: Brandon DeRosier <x@bdero.me>

python/python.sh

@@ -15,9 +15,10 @@ while [[ -h "$SOURCE" ]]; do
 done
 DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
 
-if [[ "$OSTYPE" = *"darwin"* ]];
-then
+if [[ "$OSTYPE" == *"darwin"* ]]; then
     PYTHON=$DIR/runtime/python-3.7.10-rev1-darwin/Python.framework/Versions/3.7/bin/python3
+elif [[ "$OSTYPE" == "msys" ]]; then
+    PYTHON=$DIR/runtime/python-3.7.10-rev1-windows/python/python.exe
 else
     PYTHON=$DIR/runtime/python-3.7.10-rev2-linux/python/bin/python
 fi