Update patch version for release - new version is 1.5.18-dev

Change-Id: Ib629108124e68f2551b92cfa6e85172366b6039c
diff --git a/src/main/java/com/android/tools/r8/Version.java b/src/main/java/com/android/tools/r8/Version.java
index 65ee864..c138ee9 100644
--- a/src/main/java/com/android/tools/r8/Version.java
+++ b/src/main/java/com/android/tools/r8/Version.java
@@ -11,7 +11,7 @@
 
   // This field is accessed from release scripts using simple pattern matching.
   // Therefore, changing this field could break our release scripts.
-  public static final String LABEL = "1.5.17-dev";
+  public static final String LABEL = "1.5.18-dev";
 
   private Version() {
   }