Checking in changes prior to tagging of version 0.2.0.

Changelog diff is:

diff --git a/History.md b/History.md
index 8606d29..74e502f 100644
--- a/History.md
+++ b/History.md
@@ -1,7 +1,12 @@
+0.2.0 / 2013-03-18
+==================
+
+  * Add: The option which specifies arbitrary hash seed.
+
 0.1.7 / 2013-02-21
 ==================

-  * Chage test runner to Mocha.
+  * Change test runner to Mocha.

 0.1.6 / 2013-02-13
 ==================