tree d8d45ab3f05d6b5538b419eab19ac5244f7808fe
parent 8d0b229e78b124c1e250c17299c6a3efa822fefb
author Korn, Uwe <Uwe.Korn@blue-yonder.com> 1538345243 -0400
committer Wes McKinney <wesm+git@apache.org> 1538345243 -0400

ARROW-3301: [Website] Update Jekyll and Bootstrap 4

Screenshot:

![127 0 0 1_4000_ ipad pro](https://user-images.githubusercontent.com/70274/45920083-b2953300-be9f-11e8-84b8-381570ae8245.png)

Author: Korn, Uwe <Uwe.Korn@blue-yonder.com>
Author: Wes McKinney <wesm+git@apache.org>

Closes #2607 from xhochy/ARROW-3301 and squashes the following commits:

0e8949aa1 <Wes McKinney> Simple text about advantages of columnar memory layout
2fb70d63a <Korn, Uwe> Remove placeholder text
b92793982 <Korn, Uwe> Add license header to main.js
c83e3db6a <Korn, Uwe> ARROW-3301:  Update Jekyll and Bootstrap 4