fix command for windows build

Author: leng-yue

build.py

@@ -5,6 +5,10 @@
 package_type = os.environ.get("PACKAGE_TYPE", "onedir")
 assert package_type in ("onedir", "onefile"), "PACKAGE_TYPE must be onedir or onefile"
 
+# upgrade dependencies manually
+if platform.system() == "Windows":
+    sp.check_call(["pip", "install", "--upgrade", "pywin32", "cffi"])
+
 sep = ";" if platform.system() == "Windows" else ":"
 
 args = [