Using matrix include and fix test bug.

.travis.yml

@@ -10,3 +10,12 @@ env:
 
 before_script:
   - "pushd tests && npm install && popd"
+
+matrix:
+  include:
+    - node_js: "6"
+      env: RUN_PHANTOMJS=0
+    - node_js: "6"
+      env: RUN_PHANTOMJS=1
+    - node_js: "8"
+      env: RUN_PHANTOMJS=0

package.json

@@ -4,7 +4,7 @@
   "description": "Ethereum wallet library.",
   "main": "index.js",
   "scripts": {
-    "test": "if [ \"$RUN_PHANTOMJS\" == \"1\" ]; then npm run-script test-phantomjs; else npm run-script test-node; fi",
+    "test": "if [ \"$RUN_PHANTOMJS\" = \"1\" ]; then npm run-script test-phantomjs; else npm run-script test-node; fi",
     "test-node": "./node_modules/.bin/mocha tests/test-*.js",
     "test-phantomjs": "./node_modules/.bin/grunt --gruntfile tests/Gruntfile.js dist && phantomjs ./node_modules/mocha-phantomjs-core/mocha-phantomjs-core.js ./tests/test.html",
     "version": "grunt dist"