Add 3.0 changelog and upgrade docs

Author: johnkary

CHANGELOG.md

@@ -1,11 +1,20 @@
-CHANGELOG for 2.0
+CHANGELOG
 =================
 
 View diff for a specific commit:  
 https://github.com/johnkary/phpunit-speedtrap/commit/XXX where XXX is the commit hash
 
 View diff between two versions:  
-https://github.com/johnkary/phpunit-speedtrap/compare/v1.1.0...v2.0.0
+https://github.com/johnkary/phpunit-speedtrap/compare/v2.0.0...v3.0.0
+
+## 3.0.0 (2018-02-24)
+
+Version 3.0 introduces support for PHPUnit 7.0+ and PHP 7.1+.
+
+Changes may be required if you have extended SpeedTrapListener. See
+[UPGRADE.md](UPGRADE.md) for upgrading your subclass to support 3.0.
+
+* [PR #41](https://github.com/johnkary/phpunit-speedtrap/pull/41) Make compatible with phpunit 7.x
 
 ## 2.0.0 (2017-12-06)
 

UPGRADE.md

@@ -1,3 +1,20 @@
+UPGRADE FROM 2.x to 3.0
+=======================
+
+### `JohnKary\PHPUnit\Listener\SpeedTrapListener` subclasses must ensure method signatures match PHPUnit TestListenerDefaultImplementation
+
+SpeedTrapListener was upgraded to support PHPUnit 7.0, which introduced a
+new trait `TestListenerDefaultImplementation` containing a few new scalar type
+hints and void return hints. SpeedTrapListener subclasses overriding any
+of the below methods will require updating the new method signatures:
+
+| Old signature | New signature |
+| -------- | --- |
+| `public function endTest(Test $test, $time)` | `public function endTest(Test $test, float $time): void`
+| `public function startTestSuite(TestSuite $suite)` | `public function startTestSuite(TestSuite $suite): void`
+| `public function endTestSuite(TestSuite $suite)` | `public function endTestSuite(TestSuite $suite): void`
+
+
 UPGRADE FROM 1.x to 2.0
 =======================