Prepare to release 1.6.6 BETA (#8547)

* Prepare to release 1.6.6 BETA

* Add info about cleaning up for WDA

CHANGELOG.md

@@ -1,3 +1,26 @@
+CHANGES IN VERSION 1.6.6-beta (from 1.6.5)
+===================================
+
+**Note:** This is a **_BETA_** release. Please direct any issues to the [Appium
+issue tracker](https://github.com/appium/appium/issues) and provide as much
+information as possible.
+
+This release exists to provide an updatable package in order to get the latest
+work on Appium. To install, first uninstall Appium and then re-install with the
+`beta` tag. To get any changes that have been published to sub-packages, simply
+repeat that process.
+```
+npm uninstall -g appium
+npm install -g appium@beta
+```
+
+If you are running iOS tests with the XCUITest backend (i.e., iOS 10+ tests, and
+some iOS 9.3 tests, if the `automationName` capability is set to `XCUITest`), you
+should also remove the old build artifacts.
+1. Remove derived data: `rm -rf ~/Library/Developer/Xcode/DerivedData/WebDriverAgent-*`
+2. Remove `WebDriverAgentRunner` application from any real device being tested.
+
+
 CHANGES IN VERSION 1.6.5 (from 1.6.4)
 ===================================
 

package.json

@@ -11,7 +11,7 @@
     "firefoxos",
     "testing"
   ],
-  "version": "1.6.5",
+  "version": "1.6.6-beta",
   "author": "https://github.com/appium",
   "license": "Apache-2.0",
   "repository": {