Add lines of code counting function

Author: CyanCoding

app/Project Tracker/Project Tracker/Statistics.cs

@@ -1,14 +1,20 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
 namespace Project_Tracker {
 	class Statistics {
 		public static int CountLines(string[] files) {
+			int linesOfCode = 0;
 
-			return -1;
+			foreach (string file in files) {
+				linesOfCode += File.ReadLines(file).Count();
+			}
+
+			return linesOfCode;
 		}