Don't print domain objects in yaml

They're hella massive and blow up the terminal because of the huge
"members" array that generally always contains at least one tap Test
object.

lib/clean-yaml-object.js

@@ -4,6 +4,7 @@ var Module = require('module')
 var fs = require('fs')
 var binpath = path.resolve(__dirname, '../bin')
 var stack = require('./stack.js')
+var Domain = require('domain').Domain
 
 function hasOwn (obj, key) {
   return Object.prototype.hasOwnProperty.call(obj, key)
@@ -36,6 +37,9 @@ function cleanTapYamlObject (object) {
 }
 
 function yamlFilter (propertyName, isRoot, source, target) {
+  if (source instanceof Domain)
+    return false
+
   if (!isRoot)
     return true
 

test/test/emitter-match--bail--buffer.tap

@@ -0,0 +1,11 @@
+TAP version 13
+not ok 1 - check ee matches ___/# time=[0-9.]+(ms)?/~~~ {
+    not ok 1 - should match pattern provided
+      ---
+      {"at":{"column":5,"file":"test/test/emitter-match.js","line":6},"found":{"_events":{},"_eventsCount":0,"_maxListeners":null,"domain":{},"truthy":false},"pattern":{"truthy":true},"source":"t.match(e, { truthy: true })\n"}
+      ...
+
+    Bail out! # should match pattern provided
+}
+Bail out! # should match pattern provided
+

test/test/emitter-match--bail.tap

@@ -0,0 +1,10 @@
+TAP version 13
+# Subtest: check ee matches
+    not ok 1 - should match pattern provided
+      ---
+      {"at":{"column":5,"file":"test/test/emitter-match.js","line":6},"found":{"_events":{},"_eventsCount":0,"_maxListeners":null,"domain":{},"truthy":false},"pattern":{"truthy":true},"source":"t.match(e, { truthy: true })\n"}
+      ...
+
+    Bail out! # should match pattern provided
+Bail out! # should match pattern provided
+

test/test/emitter-match--buffer.tap

@@ -0,0 +1,15 @@
+TAP version 13
+not ok 1 - check ee matches ___/# time=[0-9.]+(ms)?/~~~ {
+    not ok 1 - should match pattern provided
+      ---
+      {"at":{"column":5,"file":"test/test/emitter-match.js","line":6},"found":{"_events":{},"_eventsCount":0,"_maxListeners":null,"domain":{},"truthy":false},"pattern":{"truthy":true},"source":"t.match(e, { truthy: true })\n"}
+      ...
+
+    1..1
+    # failed 1 test
+}
+
+1..1
+# failed 1 test
+___/# time=[0-9.]+(ms)?/~~~
+

test/test/emitter-match.js

@@ -0,0 +1,8 @@
+var t = require('../..')
+var EE = require('events').EventEmitter
+t.test('check ee matches', function (t) {
+  var e = new EE()
+  e.truthy = false
+  t.match(e, { truthy: true })
+  t.end()
+})

test/test/emitter-match.tap

@@ -0,0 +1,15 @@
+TAP version 13
+# Subtest: check ee matches
+    not ok 1 - should match pattern provided
+      ---
+      {"at":{"column":5,"file":"test/test/emitter-match.js","line":6},"found":{"_events":{},"_eventsCount":0,"_maxListeners":null,"domain":{},"truthy":false},"pattern":{"truthy":true},"source":"t.match(e, { truthy: true })\n"}
+      ...
+
+    1..1
+    # failed 1 test
+not ok 1 - check ee matches ___/# time=[0-9.]+(ms)?/~~~
+
+1..1
+# failed 1 test
+___/# time=[0-9.]+(ms)?/~~~
+