WebUI: Update unit test README

Update link to our FreeIPA wiki page where unit tests are described.
The description of how to run those test was also updated.

https://pagure.io/freeipa/issue/6974

Reviewed-By: Petr Vobornik <pvoborni@redhat.com>

install/ui/test/README

@@ -1 +0,0 @@
-http://www.freeipa.org/page/UI_Unit_Tests

install/ui/test/README.md

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+# WebUI Unit Tests
+
+How to run tests:
+
+1. Run "autoreconf" command in the root of the repository
+2. Run "./configure" in the root of the repository
+3. Go to install/ui/src/libs/ directory
+4. Run "$ make" - this step generates loader.js which is necessary for load
+    current API version into WebUI. This version is necessary for checking
+    response of each API call.
+5. Go to install/ui/test
+6. Run "$ firefox index.html"
+
+Only Firefox browser is supported, because Google Chrome does not allow
+to fetch files using AJAX and file:// protocol.
+
+For more information about WebUI unit tests please read following:
+https://www.freeipa.org/page/FreeIPAv2:UI_Unit_Tests