prevent jest hanging after tests finish on CI (#196)

* prevent jest hanging after tests finish on CI

* add --detectOpenHandles to debug

* force exit jest

Author: mastilver

.travis.yml

@@ -14,7 +14,7 @@ install:
   - npm install webpack@$WEBPACK_VERSION extract-text-webpack-plugin@$EXTRACT_PLUGIN_VERSION || true
 
 script:
-  - npm test
+  - npm test -- --forceExit
 
 after_script:
   - $(npm bin)/codecov

spec/plugin.integration.spec.js

@@ -150,8 +150,8 @@ describe('ManifestPlugin using real fs', function() {
       hashes = [];
     });
 
-    afterAll(() => {
-      compiler.close()
+    afterAll((done) => {
+      compiler.close(done)
     })
 
     it('outputs a manifest of one file', function(done) {
@@ -198,8 +198,8 @@ describe('ManifestPlugin using real fs', function() {
       isFirstRun = true;
     });
 
-    afterAll(() => {
-      compiler.close()
+    afterAll((done) => {
+      compiler.close(done)
     })
 
     it('outputs a manifest of one file', function(done) {