Add border function in Flex class

README.md

@@ -997,6 +997,8 @@ FlexLayout also adds methods to set common UIView properties.
 Set the flex item's UIView background color. 
 * **`cornerRadius(_ value: CGFloat)`**  
 Set the flex item's UIView rounded corner radius.
+* **`border(_ width: CGFloat, _ color: UIColor)`**  
+Set the flex item's UIView border.
 
 ###### Usage examples:
 ```swift
@@ -1006,6 +1008,8 @@ Set the flex item's UIView rounded corner radius.
   }
   // Set rounded corner
   flex.addItem().cornerRadius(12)
+  // Set border
+  flex.addItem().border(1, .black)
 ```
 
 <br>

Sources/Swift/FlexLayout.swift

@@ -179,8 +179,6 @@ public final class Flex {
      Note that row and row-reverse are affected by the layout direction (see `layoutDirection` property) of the flex container.
      If its text direction is LTR (left to right), row represents the horizontal axis oriented from left to right, and row-reverse
      from right to left; if the direction is rtl, it's the opposite.
-
-     - Parameter value: Default value is .column
     */
     public var direction: Direction? {
         get {
@@ -1250,6 +1248,25 @@ public final class Flex {
             preconditionFailure("Trying to modify deallocated host view")
         }
     }
+
+    /**
+     Set the view to border width and color
+
+     - Parameters:
+       - width: border width
+       - color: border color
+     - Returns: flex interface
+     */
+    @discardableResult
+    public func border(_ width: CGFloat, _ color: UIColor) -> Flex {
+        if let host = self.view {
+            host.layer.borderWidth = width
+            host.layer.borderColor = color.cgColor
+            return self
+        } else {
+            preconditionFailure("Trying to modify deallocated host view")
+        }
+    }
 
     //
     // MARK: Display