Implement bar graph visualization of single indicators

[cjhendrix]

Using these inputs:

• XY's repo: https://github.com/OCHA-DAP/hdx-design/tree/gh-pages
• the frog prototype: http://ocha-dap.github.io/hdx-design/ (note CSS for graph elements)
• the API specification work https://github.com/OCHA-DAP/DAP-System/issues/263
• the note to be added to the graphs as shown here: https://docs.google.com/drawings/d/1OOep6FH5eDlvuqhgEII9CI_quG-xQtJTbwJ0xhYyslc/edit

Implement the bar graph (single indicator, X number of countries, latest non-null year). The task here is just to get the code working so that it can later be added to the new templates.

For the number of countries to show, this can be implemented as either:

1. a massive horizontal scroll
2. the first X countries alphabetically where X is a number that looks nice in the new template

[danmihaila]

moved to #1202