Begin development on v6.0.3

Change-Id: I0366c6a72d0e54c181bd31375a9344ccdb143926

Author: samtstern

buildSrc/src/main/kotlin/Config.kt

@@ -1,5 +1,5 @@
 object Config {
-    const val version = "6.0.2"
+    const val version = "6.0.3-SNAPSHOT"
     val submodules = listOf("auth", "auth-github", "common", "firestore", "database", "storage")
 
     private const val kotlinVersion = "1.3.10"