Bump version to 0.9.1
diff --git a/configure.ac b/configure.ac
index 3ca23ee..1adc84b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,6 +1,6 @@
 AC_PREREQ([2.64])
 AC_INIT([HarfBuzz],
-        [0.9.0],
+        [0.9.1],
         [http://bugs.freedesktop.org/enter_bug.cgi?product=harfbuzz],
         [harfbuzz],
         [http://harfbuzz.org/])