Upgrade WebKitGTK+ to 2.22.6 (#86)

Closes #85 
For security vulnerabilities: https://webkitgtk.org/security/WSA-2018-0009.html

Tested on my arm device with RNTester okay.
I don't have a Pixel phone and cannot update measurement result as these result are from Pixel phone.

Author: Kudo

README.md

@@ -48,7 +48,7 @@ Follow steps below in order for your React Native app to use new version of JSC
 1. Add `jsc-android` to the "dependencies" section in your `package.json`:
 ```diff
 dependencies {
-+  "jsc-android": "236355.x.x",
++  "jsc-android": "241213.x.x",
 ```
 
 then run `npm install` or `yarn` (depending which npm client you use) in order for the new dependency to be installed in `node_modules`
@@ -78,7 +78,7 @@ allprojects {
 
 +configurations.all {
 +    resolutionStrategy {
-+        force 'org.webkit:android-jsc:r236355'
++        force 'org.webkit:android-jsc:r241213'
 +    }
 +}
 
@@ -98,7 +98,7 @@ To use this variant instead replace the third installation step with:
 +    resolutionStrategy {
 +        eachDependency { DependencyResolveDetails details ->
 +            if (details.requested.name == 'android-jsc') {
-+                details.useTarget group: details.requested.group, name: 'android-jsc-intl', version: 'r236355'
++                details.useTarget group: details.requested.group, name: 'android-jsc-intl', version: 'r241213'
 +            }
 +        }
 +    }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "jsc-android",
-  "version": "236355.1.1",
+  "version": "241213.0.0",
   "description": "Pre-build version of JavaScriptCore to be used by React Native apps",
   "repository": {
     "type": "git",
@@ -26,7 +26,7 @@
     "start": "./scripts/start.sh"
   },
   "config": {
-    "webkitGTK": "2.22.2",
+    "webkitGTK": "2.22.6",
     "chromiumICUCommit": "b34251f8b762f8e2112a89c587855ca4297fed96"
   }
 }