Update tooling (#99)

- Update browserify, serve, and tape to the latest versions
- update the example script to reflect serve's new CLI options
- Remove the uneeded dependency on opn-cli
- Force Travis to use NPM 5.x
- Remove bower.json

package.json

@@ -21,18 +21,17 @@
     "pjax.js"
   ],
   "devDependencies": {
-    "browserify": "^3.46.0",
+    "browserify": "^15.0.0",
     "jscs": "^3.0.7",
     "jsdom": "^11.5.1",
     "jsdom-global": "^3.0.2",
     "jshint": "^2.5.6",
     "npmpub": "^3.1.0",
     "nyc": "^11.4.1",
-    "opn-cli": "^3.1.0",
-    "serve": "1.4.0",
+    "serve": "^6.4.4",
     "tap-nyc": "^1.0.3",
     "tap-spec": "^4.1.1",
-    "tape": "^3.0.0"
+    "tape": "^4.8.0"
   },
   "scripts": {
     "lint": "jscs . && jshint . --exclude-path .gitignore",
@@ -42,7 +41,7 @@
     "test": "npm run lint && npm run tests | tap-spec",
     "coverage-tests": "npm run tests | tap-nyc",
     "coverage": "nyc -x \"tests/**\" npm run coverage-tests",
-    "example": "opn http://localhost:3000/example/; serve .",
+    "example": "serve -o -p 3000 ./example",
     "prepublish": "npm run standalone",
     "#release": "testling does not work in a process launch by npm... :facepalm:",
     "release": "echo \"npmpub --skip-test --dry && npm test && npmpub --skip-test --skip-cleanup\""