add Kotlin support

Kotlin/XOREncryption.kt

@@ -0,0 +1,20 @@
+fun encryptDecrypt(input: String): String {
+    val key = charArrayOf('K', 'C', 'Q') //Can be any chars, and any length array
+    val output = StringBuilder()
+
+    for (i in 0 until input.length) {
+        val a: Int = input[i].toInt()
+        val b: Int = key[i % key.size].toInt()
+        output.append((a xor b).toChar())
+    }
+
+    return output.toString()
+}
+
+fun main(args: Array<String>) {
+    val encrypted = encryptDecrypt("kylewbanks.com")
+    println("Encrypted: $encrypted") // output: Encrypted:  :=.43*-:8m2$.
+
+    val decrypted = encryptDecrypt(encrypted)
+    println("Decrypted: $decrypted") // output: Decrypted: kylewbanks.com
+}