Update CHANGELOG.md and bump the version to 1.0.0.

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3d4d120..71a3a41 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md

@@ -1,3 +1,6 @@
+#### 1.0.0
+   * Remove _hash function and use quiver_hashcode package instead.
+
 #### 0.4.0
    * Add fromList factory constructor.
    * Add Tuple6 and Tuple7 classes.

diff --git a/pubspec.yaml b/pubspec.yaml
index 36c0339..c069f48 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml

@@ -1,5 +1,5 @@
 name: tuple
-version: 0.4.0
+version: 1.0.0
 authors:
 - Boris Kaul <localvoid@gmail.com>
 - Kwang Yul Seo <kwangyul.seo@gmail.com>