Add docs and tests for gisida-react charts

[kahummer]

The tests and documentation should be structured as pointed out in this comment. https://github.com/onaio/gisida-react/pull/147#issuecomment-643937239

• [ ] BarChartStacked

• [ ] ColumnChart.jsx

• [ ] HorizontalBarChart.jsx

• [ ] LineChart.jsx

• [ ] PieChart.jsx

• [ ] QuantColumnChart.jsx

• [ ] SumChartMinimize.jsx

• [ ] SumColumnChart.jsx

• [ ] SumPieChart.jsx

• [ ] SummaryChart.jsx