chore: Use prepare script instead of prepublish

Run `npm help scripts` in command-line for more info.

Closes apiaryio#945.

package.json

@@ -18,7 +18,7 @@
     "docs:serve": "sphinx-autobuild docs docs/_build/",
     "docs:install": "pip install -r docs/requirements.txt",
     "lint": "conventional-changelog-lint --from=master && eslint src",
-    "prepublish": "npm run build",
+    "prepare": "npm run build",
     "pretest": "npm run build",
     "semantic-release": "scripts/semantic-release.sh",
     "test": "mocha \"test/**/*-test.coffee\"",