Cannot create python environment due to broken dependency
#### Problem description
Following the  [documentation](https://pandas.pydata.org/pandas-docs/stable/contributing.html#contributing-to-pandas) I've tried to [create a python environment](https://pandas.pydata.org/pandas-docs/stable/contributing.html#creating-a-python-environment-pip)  and encountered this error message:

```bash
python -m pip install -r ci/requirements_dev.txt

Collecting PyEnchant>=1.6.5 (from sphinxcontrib-spelling->-r ci/requirements_dev.txt (line 14))
  Using cached https://files.pythonhosted.org/packages/9e/54/04d88a59efa33fefb88133ceb638cdf754319030c28aadc5a379d82140ed/pyenchant-2.0.0.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-comptn20/PyEnchant/setup.py", line 212, in <module>
        import enchant
      File "/tmp/pip-install-comptn20/PyEnchant/enchant/__init__.py", line 92, in <module>
        from enchant import _enchant as _e
      File "/tmp/pip-install-comptn20/PyEnchant/enchant/_enchant.py", line 145, in <module>
        raise ImportError(msg)
    ImportError: The 'enchant' C library was not found. Please install it via your OS package manager, or use a pre-built binary wheel from PyPI. 
```

Looking it up online I've found that the project [pyenchant](https://github.com/rfk/pyenchant) is no longer maintained.

```bash
uname -sro
Linux 4.18.10-arch1-1-ARCH GNU/Linux
```
```bash
pip -V
pip 18.0 from /path (python 3.7) 
```

```bash
pacman -Qi enchant

Name            : enchant
Version         : 2.2.3-1
Description     : A wrapper library for generic spell checking
Architecture    : x86_64
URL             : https://abiword.github.io/enchant/
Licenses        : LGPL
Groups          : None
Provides        : None
Depends On      : aspell  hunspell  hspell  libvoikko  glib2
Optional Deps   : None
Required By     : python-pyenchant  webkit2gtk
Optional For    : None
Conflicts With  : None
Replaces        : None
Installed Size  : 148.00 KiB
Packager        : Felix Yan <felixonmars@archlinux.org>
Build Date      : Thu Feb 22 11:36:06 2018
Install Date    : Sun Sep 30 16:13:39 2018
Install Reason  : Installed as a dependency for another package
Install Script  : No
Validated By    : Signature
```
