Refine setup.py to work with pip

setup.py

@@ -1,5 +1,6 @@
 from distutils.core import setup
 from distutils.command.install import install
+import sys
 
 class install_with_kernelspec(install):
     def run(self):
@@ -10,6 +11,11 @@ class install_with_kernelspec(install):
 with open('README.rst') as f:
     readme = f.read()
 
+svem_flag = '--single-version-externally-managed'
+if svem_flag in sys.argv:
+    # Die, setuptools, die.
+    sys.argv.remove(svem_flag)
+
 setup(name='bash_kernel',
       version='0.1',
       description='A bash kernel for IPython',
@@ -19,7 +25,7 @@ setup(name='bash_kernel',
       url='https://github.com/takluyver/bash_kernel',
       py_modules=['bash_kernel'],
       cmdclass={'install': install_with_kernelspec},
-      install_requires=['ipython>=3.0', 'pexpect>=3.3'],
+      install_requires=['pexpect>=3.3'],
       classifiers = [
           'Framework :: IPython',
           'License :: OSI Approved :: BSD License',