bpo-33131: Upgrade ensurepip to bundle pip 10.0.1 (GH-6546)

Upgrade ensurepip to bundle pip 10.0.1
(cherry picked from commit 0399cf9b)
Co-authored-by: Paul Moore <p.f.moore@gmail.com>

Lib/ensurepip/__init__.py

@@ -14,7 +14,7 @@ __all__ = ["version", "bootstrap"]
 
 _SETUPTOOLS_VERSION = "39.0.1"
 
-_PIP_VERSION = "9.0.3"
+_PIP_VERSION = "10.0.1"
 
 _PROJECTS = [
     ("setuptools", _SETUPTOOLS_VERSION),
@@ -28,8 +28,8 @@ def _run_pip(args, additional_paths=None):
         sys.path = additional_paths + sys.path
 
     # Install the bundled software
-    import pip
-    return pip.main(args)
+    import pip._internal
+    return pip._internal.main(args)
 
 
 def version():

Misc/NEWS.d/next/Library/2018-04-20-10-43-17.bpo-33131.L2E977.rst

+Upgrade bundled version of pip to 10.0.1.