Fixed drawing BubbleChart with only one bubble
Update lib version to 1.1
Update target SDK to 21
Update library and demo to use appcompat_v7:21 and support_v4:21
Update readme with new dependency
Added method to set PathEffect for given line on LineChart
Update readme with contributing section
Update readme with android arsenal badge
Update readme
Fixed potential problem with immutable points list in Line model

Use new ArrayList<PointView> instead Collections.emptyList()