add how to install development version

[get-me-power]

Hi!

I added how to install the development version of vint.
Please confirm this Pull Request.

[codecov-io]

Codecov Report

Merging #333 into master will decrease coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #333      +/-   ##
==========================================
- Coverage   93.69%   93.69%   -0.01%     
==========================================
  Files         133      133              
  Lines        4158     4155       -3     
  Branches      417      417              
==========================================
- Hits         3896     3893       -3     
  Misses        167      167              
  Partials       95       95

[coveralls]

Coverage decreased (-0.4%) to 95.452% when pulling cc56540 on kazukazuinaina:update_README into 9a239b2 on Kuniwak:master.

[blueyed]

Thank you. I've considered merging it, but it should be a) rephrased slightly at least (missing "the"), and b) I've thought that you should know how to install via URLs in general (although that might not be the case when you're not used to pip, of course).
Leaving it open for now.

[get-me-power]

I modified the documentation a bit.
How's this?

[blueyed]

Hmm, the first variant is actually better/easier, no?
(this one would also need a cd vint)

[get-me-power]

You are right.

How's this?

$pip install git+https://github.com/Kuniwak/vint

or

$ git clone https://github.com/Kuniwak/vint
$ cd vint
$ setup.py install

So feel free to close it in case you do not want to adopt it.

[get-me-power]

I close this pull request once.