[UITest] Try dev uitest for api25 fixes (#1242)

* [UITest] Try dev uitest for api25 fixes

* [Controls] Fix some rounding issues for UITests

* [UITest] Update to Xamarin.UITest 2.2.0 stable

* [UITests] Remove Private so dll is copied

Author: rmarinho

Xamarin.Forms.Core.Windows.UITests/Xamarin.Forms.Core.Windows.UITests.csproj

@@ -76,14 +76,6 @@
     <Reference Include="Xamarin.UITest">
       <HintPath>..\packages\Xamarin.UITest.2.2.0\lib\net45\Xamarin.UITest.dll</HintPath>
     </Reference>
-    <Reference Include="Xamarin.UITest, Version=2.1.4.0, Culture=neutral, processorArchitecture=MSIL">
-      <HintPath>..\packages\Xamarin.UITest.2.1.4\lib\net45\Xamarin.UITest.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
-    <Reference Include="Xamarin.UITest, Version=2.1.4.0, Culture=neutral, processorArchitecture=MSIL">
-      <HintPath>..\packages\Xamarin.UITest.2.1.4\lib\net45\Xamarin.UITest.dll</HintPath>
-      <Private>True</Private>
-    </Reference>
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Properties\AssemblyInfo.cs" />