安装Heroku Server的要求

Question

我目前正在尝试按照以下说明在Heroku上设置Flask网络服务器：http://virantha.com/2013/11/14/starting-a-simple-flask-app-with-heroku/

现在我正在尝试在virtualenv上安装需求，以便我可以在本地部署应用程序。但是，当我运行'pip install -r requirements.txt'时，我得到以下错误日志（包括尾部）：

Using cached idna-2.1-py2.py3-none-any.whl
Collecting imread==0.5.1 (from -r requirements.txt (line 24))
Using cached imread-0.5.1.tar.gz
  Complete output from command python setup.py egg_info:
  Traceback (most recent call last):
    File "<string>", line 1, in <module>
    File    "/private/var/folders/c3/nwlcwspn7l16n19lhzd7xky00000gn/T/pip-build-X2ZNNp/imread/setup.py", line 19, in <module>
    import numpy as np
ImportError: No module named numpy

----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/c3/nwlcwspn7l16n19lhzd7xky00000gn/T/pip-build-X2ZNNp/imread/

我尝试按照此主题中的说明修复错误：Can't install via pip because of egg_info error 但无济于事。

我想知道是否有人对我可以尝试的其他事情有任何见解，因为我已经坚持了几个小时了。

谢谢！