Added assert check for line width and added hookups to demo project

Classes/JBLineChartView.m

@@ -469,6 +469,7 @@ - (void)drawRect:(CGRect)rect
     }
 
     NSAssert([self.delegate respondsToSelector:@selector(lineColorForLineChartLineView:)], @"JBLineChartLineView // delegate must implement - (UIColor *)lineColorForLineChartLineView:(JBLineChartLineView*)lineChartLineView");
+    NSAssert([self.delegate respondsToSelector:@selector(lineWidthForLineChartLineView:)], @"JBLineChartLineView // delegate must implement - (UIColor *)lineWidthForLineChartLineView:(JBLineChartLineView*)lineChartLineView");
 
     if (self.shapeLayer == nil)
     {

JBChartViewDemo/JBChartViewDemo/Controllers/JBLineChartViewController.m

@@ -21,6 +21,7 @@
 CGFloat const kJBLineChartViewControllerChartHeaderHeight = 75.0f;
 CGFloat const kJBLineChartViewControllerChartHeaderPadding = 20.0f;
 CGFloat const kJBLineChartViewControllerChartFooterHeight = 20.0f;
+CGFloat const kJBLineChartViewControllerChartLineWidth = 6.0f;
 NSInteger const kJBLineChartViewControllerNumChartPoints = 27;
 
 // Strings
@@ -159,6 +160,11 @@ - (UIColor *)lineColorForLineChartView:(JBLineChartView *)lineChartView
     return kJBColorLineChartLineColor;
 }
 
+- (CGFloat)lineWidthForLineChartView:(JBLineChartView *)lineChartView
+{
+    return kJBLineChartViewControllerChartLineWidth;
+}
+
 - (UIColor *)selectionColorForLineChartView:(JBLineChartView *)lineChartView
 {
     return [UIColor whiteColor];