Prepare for 1.5.1.

CHANGELOG.md

 Change Log
 ==========
 
+Version 1.5.1 *(2014-05-08)*
+----------------------------
+
+ * New: `@PartMap` annotation accepts a `Map` of key/value pairs for multi-part.
+ * Fix: `MockRestAdpater` uses the `ErrorHandler` from its parent `RestAdapter`.
+ * Experimental RxJava support updated for v0.18 and is now lazily initialized.
+
+
 Version 1.5.0 *(2014-03-20)*
 ----------------------------
 

README.md

@@ -14,12 +14,12 @@ Download [the latest JAR][2] or grab via Maven:
 <dependency>
   <groupId>com.squareup.retrofit</groupId>
   <artifactId>retrofit</artifactId>
-  <version>1.5.0</version>
+  <version>1.5.1</version>
 </dependency>
 ```
 or Gradle:
 ```groovy
-compile 'com.squareup.retrofit:retrofit:1.5.0'
+compile 'com.squareup.retrofit:retrofit:1.5.1'
 ```