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Alter test threshold as libvips improved greyscale conversion

.travis.yml

@@ -1,10 +1,17 @@
+language: node_js
 node_js:
 - "0.10"
 - "0.12"
-- "1"
-- "2"
-language: node_js
+- "4"
+- "5"
+sudo: false
+addons:
+  apt:
+    sources:
+    - ubuntu-toolchain-r-test
+    packages:
+    - g++-4.8
+env:
+  CXX=g++-4.8
 script: "npm run-script test-travis"
 after_script: "npm install coveralls@2 && cat ./coverage/lcov.info | coveralls"
-before_install:
-  - curl -s https://raw.githubusercontent.com/lovell/sharp/master/preinstall.sh | sudo bash -

package.json

@@ -19,7 +19,7 @@
   "devDependencies": {
     "istanbul": "0",
     "mocha": "2",
-    "should": "4"
+    "should": "8"
   },
   "scripts": {
     "test": "mocha --reporter spec",

test/spec.js

@@ -32,7 +32,7 @@ describe('dhash', function() {
 			if (err) throw err;
 			dhash(__dirname + '/images/face-low.jpg', function(err, lowHash) {
 				if (err) throw err;
-				hamming(highHash, lowHash).should.be.below(2);
+				hamming(highHash, lowHash).should.be.below(4);
 				done();
 			});
 		});