ensure renderer and configuration are set on sampleLayer

`didSet` doesn't get called in the initializer, so the sampleLayer wouldn't get the same info until it gets updated.
Using defer here (to call didSet) as opposed to calling the code in didSet directly just because I feel it looks cleaner ¯\_(ツ)_/¯

fixes #58

Author: dmrschmidt

Sources/DSWaveformImageViews/UIKit/WaveformLiveView.swift

@@ -47,20 +47,35 @@ public class WaveformLiveView: UIView {
         self.renderer = renderer
         super.init(frame: .zero)
         self.contentMode = .redraw
+
+        defer { // will call didSet to propagate to sampleLayer
+            self.configuration = configuration
+            self.renderer = renderer
+        }
     }
 
     public override init(frame: CGRect) {
         self.configuration = Self.defaultConfiguration
         self.renderer = LinearWaveformRenderer()
         super.init(frame: frame)
         contentMode = .redraw
+
+        defer { // will call didSet to propagate to sampleLayer
+            self.configuration = Self.defaultConfiguration
+            self.renderer = LinearWaveformRenderer()
+        }
     }
 
     required init?(coder: NSCoder) {
         self.configuration = Self.defaultConfiguration
         self.renderer = LinearWaveformRenderer()
         super.init(coder: coder)
         contentMode = .redraw
+
+        defer { // will call didSet to propagate to sampleLayer
+            self.configuration = Self.defaultConfiguration
+            self.renderer = LinearWaveformRenderer()
+        }
     }
 
     /// The sample to be added. Re-draws the waveform with the pre-existing samples and the new one.