Issue #197: Doc update: install from source with pip (blais/beancount)

[pjz]

New issue 197: Doc update: install from source with pip
https://bitbucket.org/blais/beancount/issues/197/doc-update-install-from-source-with-pip

pjz:

pip can now install from an hg repo. See [here](https://pip.pypa.io/en/latest/reference/pip_install/#vcs-support) for details, but the upshot is you can do:


```
#!bash

pip install hg+https://bitbucket.org/blais/beancount#egg=beancount

```

and end up with it installed from source. Upgrades should work too.