Warn for unnecessary usings

Author: jnm2

.editorconfig

@@ -2,6 +2,9 @@
 
 dotnet_sort_system_directives_first = true
 
+# IDE0005: Using directive is unnecessary.
+dotnet_diagnostic.IDE0005.severity = warning
+
 # CS8509: The switch expression does not handle all possible values of its input type (it is not exhaustive).
 dotnet_diagnostic.CS8509.severity = none
 

src/TfvcMigrator/Program.cs

@@ -2,7 +2,6 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.CommandLine;
-using System.CommandLine.Invocation;
 using System.Globalization;
 using System.IO;
 using System.Linq;

src/TfvcMigrator/TopologicalSortExtensions.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
-using System.Diagnostics;
 using System.Linq;
 
 namespace TfvcMigrator