Chore: 2.1.0

# [2.1.0](v2.0.1...v2.1.0) (2021-03-12)

## New
* Add the Contact Changing functionality to the database and backend
* Add the Contact Changing functionality to the database and backend

src/Database/Database.csproj

-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 	<PropertyGroup>
 		<OutputType>Library</OutputType>
 		<RootNamespace>Coscine.Database</RootNamespace>
 		<AssemblyName>Coscine.Database</AssemblyName>
 		<TargetFrameworks>net5.0;net461</TargetFrameworks>
-		<Version>2.0.1</Version>
+		<Version>2.1.0</Version>
 	</PropertyGroup>
 	<PropertyGroup>
 		<Authors>RWTH Aachen University</Authors>

src/Scaffolding/DataModel/Model.cs

-using System;
+using System;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Metadata;