Screenshot tests (#130)

* #9 Add snapshot testing library

* #9 Create script to boot test simulators

* #9 Create the UI test plan

* #9 Create shared schemes for test targets

* #9 Disable split view for UI tests

* #9 Fix fastlane dependencies

* #9 Add snapshot testing to the application

* #9 assert screenshots

* #9 fix swipe gestures on iPad

* #9 Fix accessing items in session verification screen

* #9 Workaround for flaky unit test

* #9 Specify scheme for alpha build

* #9 Add reference screenshots

* Update python script path and check assets for png check

* Update script path

* Use static timezone for simulator time

* Fix build after SwiftFormat

* Add changelog

* Upload failed screenshots artifact

* Always upload artifacts

* Update boot simulator script

* Update simulator overridden time

* Install pytz before tests

* Get time from Ruby script

* Disable SwiftUI animation when running UI tests

* Update screenshots after animation setting

* Include reference images in the artifact

* Update matching precision

* Update image matching precision & revert artifact content

* Include Xcode result in the artifact

* Update test output directory

* Disable gradient on splash screen for tests

* Tap next button explicitly

* Wait a bit before checking alert

* Wait 1 second

* Run SwiftFormat on project

* Ignore temporary screenshots

* Fix most of the PR remarks

* Fix conflicts

* Bump Python version to 3

* Update reference screenshots for authentication screens

* Update SwiftFormat

* Fix flakey session verification test.

* Update scheme.

Co-authored-by: Doug <douglase@element.io>

UnitTests/SupportingFiles/target.yml

@@ -1,5 +1,29 @@
 name: UnitTests
 
+schemes:
+  UnitTests:
+    analyze:
+      config: Debug
+    archive:
+      config: Release
+    build:
+      targets:
+        UnitTests: all
+    profile:
+      config: Release
+    run:
+      config: Debug
+      disableMainThreadChecker: false
+      environmentVariables:
+        IS_RUNNING_UNIT_TESTS: "1"
+    test:
+      config: Debug
+      disableMainThreadChecker: false
+      captureScreenshotsAutomatically: false
+      gatherCoverageData: true
+      targets:
+      - UnitTests
+
 targets:
   UnitTests:
     type: bundle.unit-test