Releasing version 1.5.0

Author: LaunchDarklyReleaseBot

src/LaunchDarkly.TestHelpers/LaunchDarkly.TestHelpers.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <Version>1.4.0</Version>
+    <Version>1.5.0</Version>
     <!-- The BUILDFRAMEWORKS variable allows us to override the target frameworks with a
          single framework that we are testing; this allows us to test with older SDK
          versions that would error out if they saw any newer target frameworks listed