ci: update semantic-release

Hoping that setting everything up again with a newer version will fix
the issue where Travis was not publishing to npm (invalid npm token).

Author: macklinu

.travis.yml

@@ -1,23 +1,16 @@
 language: node_js
 cache:
   yarn: true
+  directories:
+    - ~/.npm
 notifications:
   email: false
 node_js:
-  - 8
-  - 6
-  - 4
-before_install:
-  - yarn global add greenkeeper-lockfile@1
-before_script:
-  - greenkeeper-lockfile-update
-  - npm prune || true
-script:
-  - yarn test
-after_script:
-  - greenkeeper-lockfile-upload
+  - '10'
+  - '8'
+  - '6'
 after_success:
-  - npm run semantic-release
+  - npm run travis-deploy-once "npm run semantic-release"
 branches:
   except:
     - /^v\d+\.\d+\.\d+$/

package.json

@@ -13,9 +13,9 @@
     "build": "tsc -p tsconfig.json",
     "lint": "tslint 'src/**/*.ts'",
     "test": "jest --env=node",
-    "predocs": "rm -rf docs/",
-    "prepublish": "npm run build",
-    "semantic-release": "semantic-release pre && npm publish && semantic-release post"
+    "prepublishOnly": "npm run build",
+    "semantic-release": "semantic-release",
+    "travis-deploy-once": "travis-deploy-once"
   },
   "repository": {
     "type": "git",
@@ -42,7 +42,8 @@
     "jest": "^21.2.1",
     "lint-staged": "^4.0.0",
     "prettier": "^1.14.3",
-    "semantic-release": "^6.3.6",
+    "semantic-release": "^15.9.17",
+    "travis-deploy-once": "^5.0.9",
     "ts-jest": "^21.1.3",
     "tslint": "^5.11.0",
     "tslint-config-prettier": "^1.15.0",