React Native Charts Wrapper Versions Save

revert Charts version back to 3.1.1, because of bugs of Charts 3.2.0. https://github.com/danielgindi/Charts/issues/3673 https://github.com/danielgindi/Charts/issues/3671

Some bug fixes.

Add stock k line example.

add support for linkage chart. Multiple charts can be synchronized at native side.

bug fix for setDataAndLockIndex. swift 4.2 is required.

Support for Swift 4.2 and Xcode 10.

Don't use if you are NOT using Swift 4.2

setDataAndLockIndex is important when you implement dynamic scroll chart. Data is load in backend, and chart view remains unchanged. Check examples-> infiniteScrollLineChart for detail.

fix Charts version to 3.1.1

1. fix fitScreen for iOS
2. add missing properties for CombineChart
3. force chart.notifyDataSetChanged() for every setState, this can fix setting axisMinimum/axisMaximum without changing data, but slow down performance if setState is called frequently.

1. cocoapods support.
2. fix visibleRange
3. more settings for radar chart.
4. Add IndexValueFormatter. Now both axis and data support valueFormatter.
5. add highlights function
6. fix collision with react-native-maps

Swift 4.1 is required for 0.4.3.

#209 add x and y PieChartDataSet ValuePosition prop #210 Fix chart frame being mispositioned #217 Docs for react-native-charts-wrapper #219 NormalizeSizeEnabled for Bubble Charts

Fix highlight in CombinedChart Fix drawEntryLabels in PieChart Add left, right, top, bottom in gesture callback.

Android and iOS gesture support. Enable calling function on chart instance directly.