remove readlink (#9649)

tools/pip_install.py

@@ -11,11 +11,9 @@ import subprocess
 import sys
 import tempfile
 
-import readlink
-
 
 def find_tools_path():
-    return os.path.dirname(readlink.main(__file__))
+    return os.path.dirname(os.path.realpath(__file__))
 
 
 def call_with_print(command, env=None):

tools/readlink.py

@@ -1,17 +0,0 @@
-#!/usr/bin/env python
-"""Canonicalizes a path and follows any symlinks.
-
-This is the equivalent of `readlink -f` on many Linux systems. This is
-useful as there are often differences in readlink on different
-platforms.
-
-"""
-import os
-import sys
-
-
-def main(link):
-    return os.path.realpath(link)
-
-if __name__ == '__main__':
-    print(main(sys.argv[1]))