Merge pull request #73 from NatchEurope/dependabot/nuget/Microsoft.Graph-4.15.0

Bump Microsoft.Graph from 4.12.0 to 4.15.0

Author: DavidDeSloovere

src/FluentEmail.Graph/FluentEmail.Graph.csproj

@@ -41,7 +41,7 @@
     <PackageReference Include="JetBrains.Annotations" Version="2021.3.0">
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="Microsoft.Graph" Version="4.12.0" />
+    <PackageReference Include="Microsoft.Graph" Version="4.15.0" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>