Could not find any downloads that satisfy the requ

I tried to install MeetMe newrelic-plugin-agent as described in https://github.com/MeetMe/newrelic-plugin-agent with PIP

but, I have this error message :

#pip install newrelic-plugin-agent

Downloading/unpacking newrelic-plugin-agent
  Real name of requirement newrelic-plugin-agent is newrelic_plugin_agent
  Could not find any downloads that satisfy the requirement newrelic-plugin-agent
No distributions at all found for newrelic-plugin-agent

The logs are :

------------------------------------------------------------
/usr/local/bin/pip run on Sun Jun 23 12:21:48 2013
Downloading/unpacking newrelic-plugin-agent

  Getting page https://pypi.python.org/simple/newrelic-plugin-agent/
  Could not fetch URL https://pypi.python.org/simple/newrelic-plugin-agent/: HTTP Error 404: Not Found (newrelic_plugin_agent does not have any     releases)
  Will skip URL https://pypi.python.org/simple/newrelic-plugin-agent/ when looking for download links for newrelic-plugin-agent
  Getting page https://pypi.python.org/simple/
  Real name of requirement newrelic-plugin-agent is newrelic_plugin_agent

  URLs to search for versions for newrelic-plugin-agent:
  * https://pypi.python.org/simple/newrelic_plugin_agent/
  Getting page https://pypi.python.org/simple/newrelic_plugin_agent/
  Could not fetch URL https://pypi.python.org/simple/newrelic_plugin_agent/: HTTP Error 404: Not Found (newrelic_plugin_agent does not have any     releases)
  Will skip URL https://pypi.python.org/simple/newrelic_plugin_agent/ when looking for download links for newrelic-plugin-agent
  Could not find any downloads that satisfy the requirement newrelic-plugin-agent

Thanks for your help.

After installing the Plugin Agent today on Ubuntu 12.04, I enhanced the guide that MeetMe provides. Try the following steps:

Install pip:

$ sudo apt-get install python-pip python-dev build-essential

$ sudo pip install --upgrade pip

$ sudo pip install --upgrade virtualenv
For certain plugins there might be additional installations, so check out the plugin instructions. [MongoDB plugin for example needs python driver for Mongo]
Copy the configuration file example to /etc/newrelic/newrelic_plugin_agent.cfg and edit the configuration in that file to enable the plugin and set the New Relic license key:

$ sudo cp /opt/newrelic_plugin_agent/etc/newrelic/newrelic_plugin_agent.cfg /etc/newrelic/newrelic_plugin_agent.cfg
Change ownership of newrelic folders to newrelic user:

$ sudo chown newrelic:newrelic /var/run/newrelic

$ sudo chown newrelic:newrelic /var/log/newrelic
Run the agent:

$ sudo newrelic_plugin_agent -c /etc/newrelic/newrelic_plugin_agent.cfg
If the process is not staying up try to run it as foreground process and check out the output:

$ sudo newrelic_plugin_agent -c /etc/newrelic/newrelic_plugin_agent.cfg -f