[VERSION] Move version script to the project root (#2556)

python/update_version.py → version.py

@@ -46,8 +46,7 @@ def update(file_name, pattern, repl):
 
 
 def main():
-    curr_dir = os.path.dirname(os.path.abspath(os.path.expanduser(__file__)))
-    proj_root = os.path.abspath(os.path.join(curr_dir, ".."))
+    proj_root = os.path.dirname(os.path.abspath(os.path.expanduser(__file__)))
     # python path
     update(os.path.join(proj_root, "python", "tvm", "_ffi", "libinfo.py"),
            r"(?<=__version__ = \")[.0-9a-z]+", __version__)