Update the solution to allow the use of C# 7

sharwell · sharwell · commit 1b5a65d9e4e9 · 2018-08-06T06:37:38.000-05:00
diff --git a/AsyncUsageAnalyzers/Directory.build.props b/AsyncUsageAnalyzers/Directory.build.props
@@ -17,7 +17,7 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <LangVersion>6</LangVersion>
+    <LangVersion>7</LangVersion>
     <Features>strict</Features>
   </PropertyGroup>
 
