Issue with packages with hyphen in the name

[benchstr]

I believe there is an issue where if a file has a hyphen in the name pip expects it to be linked to a href with an underscore instead of a hyphen, at least this seems to be the case for python-dateutil

https://pypi.org/simple/python-dateutil/
<a href="https://files.pythonhosted.org/packages/74/68/d87d9b36af36f44254a8d512cbfc48369103a3b9e474be9bdfe536abfc45/python_dateutil-2.7.5-py2.py3-none-any.whl#sha256=063df5763652e21de43de7d9e00ccf239f953a832941e37be541614732cdfc93" data-requires-python="&gt;=2.7, !=3.0.*, !=3.1.*, !=3.2.*">python_dateutil-2.7.5-py2.py3-none-any.whl</a>

dir2pi seems to want to preserve the hyphen which is causing packages to be missing

[root@centos ~]# pip install python-dateutil -v
Created temporary directory: /tmp/pip-ephem-wheel-cache-cE2aPS
Created temporary directory: /tmp/pip-req-tracker-poEmTp
Created requirements tracker '/tmp/pip-req-tracker-poEmTp'
Created temporary directory: /tmp/pip-install-NCWRIN
Looking in indexes: http://0.0.0.0/PyPI/simple
Collecting python-dateutil
  1 location(s) to search for versions of python-dateutil:
  * http://0.0.0.0/PyPI/simple/python-dateutil/
  Getting page http://0.0.0.0/PyPI/simple/python-dateutil/
  Starting new HTTP connection (1): 0.0.0.0:80
  http://0.0.0.0:80 "GET /PyPI/simple/python-dateutil/ HTTP/1.1" 200 106
  Analyzing links from page http://0.0.0.0/PyPI/simple/python-dateutil/
    Skipping link http://0.0.0.0/PyPI/simple/python-dateutil/python-dateutil-2.7.5-py2.py3-none-any.whl (from http://0.0.0.0/PyPI/simple/python-dateutil/); wrong project name (not python-dateutil)
  Could not find a version that satisfies the requirement python-dateutil (from versions: )
Cleaning up...
Removed build tracker '/tmp/pip-req-tracker-poEmTp'
No matching distribution found for python-dateutil
Exception information:
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/pip/_internal/cli/base_command.py", line 143, in main
    status = self.run(options, args)
  File "/usr/lib/python2.7/site-packages/pip/_internal/commands/install.py", line 318, in run
    resolver.resolve(requirement_set)
  File "/usr/lib/python2.7/site-packages/pip/_internal/resolve.py", line 102, in resolve
    self._resolve_one(requirement_set, req)
  File "/usr/lib/python2.7/site-packages/pip/_internal/resolve.py", line 256, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "/usr/lib/python2.7/site-packages/pip/_internal/resolve.py", line 209, in _get_abstract_dist_for
    self.require_hashes
  File "/usr/lib/python2.7/site-packages/pip/_internal/operations/prepare.py", line 218, in prepare_linked_requirement
    req.populate_link(finder, upgrade_allowed, require_hashes)
  File "/usr/lib/python2.7/site-packages/pip/_internal/req/req_install.py", line 164, in populate_link
    self.link = finder.find_requirement(self, upgrade)
  File "/usr/lib/python2.7/site-packages/pip/_internal/index.py", line 621, in find_requirement
    'No matching distribution found for %s' % req
DistributionNotFound: No matching distribution found for python-dateutil

This is what my test repo looks like

view-source:http://0.0.0.0/PyPI/simple/python-dateutil/
<a href='python-dateutil-2.7.5-py2.py3-none-any.whl'>python-dateutil-2.7.5-py2.py3-none-any.whl</a><br />