update support files

README.md

@@ -1,16 +1,11 @@
 # Amp [![Build Status](https://travis-ci.org/amphp/amp.svg?branch=v1.0.x)](https://travis-ci.org/amphp/amp)
 
-`amphp/amp` is a non-blocking concurrency framework for PHP applications.
-
-Learn more about Amp in the [Amp Guide](https://stackedit.io/viewer#!url=https://raw.githubusercontent.com/amphp/amp/master/guide.md).
+`amphp/amp` is a non-blocking concurrency framework for PHP applications. Learn more about Amp in the
+[Guide](https://stackedit.io/viewer#!url=https://raw.githubusercontent.com/amphp/amp/master/guide.md).
 
 **Dependencies**
 
-- PHP 5.5+
-
-Optional PHP extensions may be used to improve performance in production environments and react to process control signals:
-
-- [php-uv](https://github.com/chobie/php-uv) extension for libuv backends
+- PHP 7
 
 **Installation**
 
@@ -24,7 +19,11 @@ $ git clone https://github.com/amphp/amp.git
 $ composer require amphp/amp
 ```
 
+The appropriate composer versions:
+
+    - PHP7:     "v2.0.0-dev"
+    - PHP5.5+:  "v1.0.0-dev"
+
 **Versioning**
 
-Amp is currently in the process of finalizing a v1.0.0 release. The project strives to follow the
-SemVer specification.
+Amp strives to follow the SemVer specification.

composer.json

@@ -35,7 +35,10 @@
             "Amp\\Test\\": "test/"
         }
     },
-    "suggest": {
-      "php-uv": "Extension for libuv backends (high performance use cases)."
+    "extra": {
+        "branch-alias": {
+            "dev-master": "2.0.0-dev"
+            "dev-v1.0.x": "1.0.0-dev"
+        }
     }
 }