feat(release): replace semantic-release dep with Travis build stages

This makes CI quicker, and releases more stable.

Connects pelias/api#1187

.travis.yml

@@ -11,8 +11,12 @@ matrix:
 script: npm run travis
 before_install:
   - npm i -g npm
-after_success:
-  - npx semantic-release
 branches:
   except:
     - /^v\d+\.\d+\.\d+$/
+jobs:
+  include:
+    - stage: release
+      node_js: 10
+      script: curl "https://raw.githubusercontent.com/pelias/ci-tools/master/semantic-release.sh" | bash -
+      if: branch = master

package.json

@@ -26,8 +26,7 @@
     "jshint": "^2.8.0",
     "precommit-hook": "^3.0.0",
     "tap-dot": "^2.0.0",
-    "tape": "^4.6.2",
-    "semantic-release": "^15.5.0"
+    "tape": "^4.6.2"
   },
   "pre-commit": [
     "lint",