Add a unit test

mobile/.gitignore

@@ -4,4 +4,3 @@ release/
 
 # tests aren't ready yet
 /src/androidTest
-/src/test

mobile/src/test/java/be/mygod/vpnhotspot/room/ConvertersTest.kt

@@ -0,0 +1,13 @@
+package be.mygod.vpnhotspot.room
+
+import org.junit.Assert.*
+import org.junit.Test
+
+class ConvertersTest {
+    @Test
+    fun macSerialization() {
+        for (test in listOf("01:23:45:67:89:ab", "DE:AD:88:88:BE:EF")) {
+            assertTrue(test.equals(test.macToLong().macToString(), true))
+        }
+    }
+}