Update changelog and README for release 3.6.4 (#65)

Author: boyxgc

CHANGELOG.md

@@ -7,12 +7,14 @@ file [H3Core.java](./src/main/java/com/uber/h3core/H3Core.java), and support
 for the Linux x64 and Darwin x64 platforms.
 
 ## [Unreleased]
+
+## [3.6.4] - 2020-06-29
 ### Changed
 - Updated the core library to v3.6.4. (#64)
 - Updated the core library to v3.6.3. (#61)
 
 ## [3.6.3] - 2020-01-10
-## Changed
+### Changed
 - Avoid reloading the native library once loaded (#58)
 
 ## [3.6.2] - 2019-12-16

README.md

@@ -19,14 +19,14 @@ Add it to your pom.xml:
 <dependency>
     <groupId>com.uber</groupId>
     <artifactId>h3</artifactId>
-    <version>3.6.3</version>
+    <version>3.6.4</version>
 </dependency>
 ```
 
 Or, using Gradle:
 
 ```gradle
-compile("com.uber:h3:3.6.3")
+compile("com.uber:h3:3.6.4")
 ```
 
 Encode a location into a hexagon address: