Add onSubtractTime and onAddTime hooks (#508)

Daan De Deckere

2018-02-12 d40f6d89bf9084e5d03df1aeea8bffd67662f0c0

 .travis.yml

@@ -1,6 +1,16 @@
language: node_js
sudo: false
os:
  - linux
  - windows
node_js:
- '0.12'
- 'iojs'
script: npm run test
  - '7'
  - '8'
  - 'stable'
script:
  - npm run lint
  - npm run test:all
before_install:
- export TZ=Europe/Stockholm
notifications:
  email: false