Bump AutoMapper from 7.0.1 to 8.0.0 (#46)

Bumps [AutoMapper](https://github.com/AutoMapper/AutoMapper) from 7.0.1 to 8.0.0.
- [Release notes](https://github.com/AutoMapper/AutoMapper/releases)
- [Commits](AutoMapper/AutoMapper@v7.0.1...v8.0.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot[bot]

Benchmarks/Boxed.Mapping.Benchmark/Boxed.Mapping.Benchmark.csproj

@@ -15,7 +15,7 @@
   </ItemGroup>
 
   <ItemGroup Label="Package References">
-    <PackageReference Include="AutoMapper" Version="7.0.1" />
+    <PackageReference Include="AutoMapper" Version="8.0.0" />
     <PackageReference Include="BenchmarkDotNet" Version="0.11.2" />
     <PackageReference Include="StyleCop.Analyzers" PrivateAssets="All" Version="1.1.0-beta009" />
   </ItemGroup>