v0.62

add androidSourcesJar

v0.61

do not call drawBarIndicator when getYAxis()==null

v0.60

change version v0.60

v0.6

1. getYAxis() can be null.for no popup requirement.
   2.maxVisibleCount
   3.current selection

v0.51

fix a bug for invalidate not working.

v0.5

1. Add snap scroll.
   2.Add scroll end callback.

v0.4

reduce targetSdkVersion to 26.

v0.3

add bar chart.