Fix test after internal constant was moved in Amazon.Lambda.Core (#42)

Author: normj

Libraries/test/Amazon.Lambda.Core.Tests/TraveProviderTests.cs

@@ -24,7 +24,7 @@ public void SetTraceIdNoMultiConcurrency()
         [Fact]
         public async Task SetTraceIdWithMultiConcurrency()
         {
-            Environment.SetEnvironmentVariable(LambdaTraceProvider.ENV_VAR_AWS_LAMBDA_MAX_CONCURRENCY, "2");
+            Environment.SetEnvironmentVariable(Constants.ENV_VAR_AWS_LAMBDA_MAX_CONCURRENCY, "2");
             try
             {
                 var successCount = 0;
@@ -48,7 +48,7 @@ public async Task SetTraceIdWithMultiConcurrency()
             }
             finally
             {
-                Environment.SetEnvironmentVariable(LambdaTraceProvider.ENV_VAR_AWS_LAMBDA_MAX_CONCURRENCY, null);
+                Environment.SetEnvironmentVariable(Constants.ENV_VAR_AWS_LAMBDA_MAX_CONCURRENCY, null);
             }
         }
     }