Bump version number to 1.5.7.
diff --git a/configure.ac b/configure.ac
index f480ed5..bc9da58 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-AC_INIT([cgminer], [1.5.6])
+AC_INIT([cgminer], [1.5.7])
AC_PREREQ(2.59)
AC_CANONICAL_SYSTEM