fix redundant exit message (#551)

Remove the `exit` event handler which would create duplicate
activity events on a crash.

Author: juliangruber

lib/zinnia.js

@@ -163,6 +163,7 @@ const catchChildProcessExit = async ({
     const tasks = childProcesses.map(p => (async () => {
       try {
         await p
+        onActivity({ type: 'info', message: `${capitalize(module)} exited` })
       } catch (err) {
         // When the child process crash, attach the module name & the exit reason to the error object
         const exitReason = p.exitCode
@@ -294,12 +295,6 @@ export async function run ({
       resetTimeout()
       process.stderr.write(data)
     })
-
-    childProcess.on('exit', (code, signal) => {
-      const exitReason = signal ? `via signal ${signal}` : `with code: ${code}`
-      const msg = `${capitalize(module)} exited ${exitReason}`
-      onActivity({ type: 'info', message: msg })
-    })
   }
 
   try {