Reworking exception handling logic around verifyLog

Modifying exception handling logic around verifyLog in response to review feedback

When process is alive or exited normally, the exception flows through as is
When process exited abnormally, the exception is wrapped in another exception that indicates the abnormal termination

Author: dougqh

dd-smoke-tests/src/main/groovy/datadog/smoketest/AbstractServerSmokeTest.groovy

@@ -85,11 +85,20 @@ abstract class AbstractServerSmokeTest extends AbstractSmokeTest {
         try {
           verifyLog(idx, outputFile)
         } catch ( FileNotFoundException e ) {
-          if ( !testedProcesses[idx].isAlive() && testedProcesses[idx].exitValue() == 0 ) {
-            // suppress file not found exception if process exited abnormally
-            // just creates confusing noise
+          if ( testedProcesses[idx].isAlive() ) {
             throw e
           }
+
+          def exitCode = testedProesses[idx].exitValue()
+          if ( exitCode == 0 ) {
+            throw e
+          } else {
+            def logFile = logFilePaths[idx]
+              // highlight when process exited abnormally, since that may have contributed 
+              // to the log verification failure
+              throw new RuntimeException(
+                "Server process exited abnormally - exit code: ${exitCode}; check log file: ${logFile}", e)
+          }
         }
       }
     }