Add Plus image.

Author: jaclync

WooCommerce/Classes/Extensions/UIImage+Woo.swift

@@ -300,6 +300,12 @@ extension UIImage {
             .imageFlippedForRightToLeftLayoutDirection()
     }
 
+    /// Plus Icon
+    ///
+    static var plusImage: UIImage {
+        return UIImage.gridicon(.plus)
+    }
+
     /// Search Icon
     ///
     static var searchImage: UIImage {

WooCommerce/WooCommerceTests/Extensions/IconsTests.swift

@@ -139,6 +139,10 @@ final class IconsTests: XCTestCase {
         XCTAssertNotNil(UIImage.moreImage)
     }
 
+    func testPlusImageIconIsNotNil() {
+        XCTAssertNotNil(UIImage.plusImage)
+    }
+
     func testPriceImageIconIsNotNil() {
         XCTAssertNotNil(UIImage.priceImage)
     }