自定义SegmentControl，可以选择红点、动态调节segment宽度，以及滚动。
var frame = CGRect(x: 10.0, y: 130.0, width: self.view.bounds.size.width - 20.0, height: 44.0)
let segmentControl = JTSegmentControl(frame: frame)
segmentControl.delegate = self
segmentControl.items = ["first", "second", "third", "fouth"]
segmentControl.showBridge(show: true, index: 1)
segmentControl.autoScrollWhenIndexChange = false
view.addSubview(segmentControl)Width is divide equally . This is have bridge and not scrolling when index changed.(宽度根据bounds进行平分，展示红点，选择item的时候不自动调整位置)
Init JTSegmentControl,auto to set itemView's width in scrollView, scrolling when index changed.（在一个ScrollView里，根据内容自动调整每个item的宽度，同时，选择item的时候自动调整它的位置。）
frame = CGRect(x: 10.0, y: 250.0, width: self.view.bounds.size.width - 20.0, height: 44.0)
let autoWidthControl = JTSegmentControl(frame: frame)
autoWidthControl.delegate = self
autoWidthControl.items = ["first", "second", "third", "fouth", "fifth", "sixth", "seventh", "eighth"]
autoWidthControl.selectedIndex = 1
autoWidthControl.autoAdjustWidth = true
autoWidthControl.bounces = true
view.addSubview(autoWidthControl)func didSelected(segement: JTSegmentControl, index: Int) // JTSegmentPattern.swift
static let itemTextColor
static let itemSelectedTextColor
static let itemBackgroundColor
static let itemSelectedBackgroundColor
//MARK - Text font
static let textFont
static let selectedTextFont
//MARK - slider
static let sliderColor
static let sliderHeight
//MARK - bridge
static let bridgeColor