Pip install of version 0.24 is broken for platforms without wheels
#### Code Sample, a copy-pastable example if possible
Easiest way to reproduce this is in a fresh docker container, as below
```bash
docker run --rm -it alpine:latest
$ apk update
$ apk add build-base python3 python3-dev py3-pip
$ pip3 install pandas
Collecting pandas
  Downloading https://files.pythonhosted.org/packages/81/fd/b1f17f7dc914047cd1df9d6813b944ee446973baafe8106e4458bfb68884/pandas-0.24.1.tar.gz (11.8MB)
    100% |████████████████████████████████| 11.8MB 4.2MB/s 
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "/usr/lib/python3.6/site-packages/pkg_resources/__init__.py", line 346, in get_provider
        module = sys.modules[moduleOrReq]
    KeyError: 'numpy'
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-y3ff_xpr/pandas/setup.py", line 732, in <module>
        ext_modules=maybe_cythonize(extensions, compiler_directives=directives),
      File "/tmp/pip-install-y3ff_xpr/pandas/setup.py", line 475, in maybe_cythonize
        numpy_incl = pkg_resources.resource_filename('numpy', 'core/include')
      File "/usr/lib/python3.6/site-packages/pkg_resources/__init__.py", line 1136, in resource_filename
        return get_provider(package_or_requirement).get_resource_filename(
      File "/usr/lib/python3.6/site-packages/pkg_resources/__init__.py", line 348, in get_provider
        __import__(moduleOrReq)
    ModuleNotFoundError: No module named 'numpy'
```

#### Problem description

Note that pip installing numpy and then pandas does work
```bash
pip3 install numpy
pip3 install pandas
```
But the standalone command is broken.
```bash
pip3 install pandas
```

Unfortunately, this means that a requirements.txt file is insufficient to for setting up a new environment with pandas installed (like in a docker container).