Test user specified callback to wrapped module.

Closes #86.

release.md

@@ -0,0 +1,3 @@
+### Issue by Issue
+
+ * Test user specified callback to wrapped module. #86.

t/main/executable.t.js

@@ -1,11 +1,13 @@
 #!/usr/bin/env node
 
-require('proof')(1, function (ok, equal) {
+require('proof')(2, function (ok, equal) {
     var echo = require('./fixtures/echo')
     var stream = require('stream')
     var stdout = new stream.PassThrough
     var chunks = []
     stdout.on('data', function (data) { chunks.push(data.toString()) })
-    echo([ 'a', 'b' ], stdout)
+    echo([ 'a', 'b' ], stdout, null, null, function () {
+        ok(1, 'called back')
+    })
     equal(chunks.join(''), 'a b\n', 'executable')
 })

t/main/fixtures/echo.js

@@ -6,7 +6,7 @@
   ___ usage ___
 */
 
-require('../../../executable')(module, function (options, stdout) {
+require('../../../executable')(module, function (options, stdout, stderr, stdin, callback) {
     if (options.argv.length) {
         var separator = ''
         options.argv.forEach(function (arg) {
@@ -16,4 +16,5 @@ require('../../../executable')(module, function (options, stdout) {
         })
         stdout.write('\n')
     }
+    callback()
 })