Merge branch 'develop' into rollForward

.travis.yml

@@ -1,16 +1,21 @@
 language: node_js
-sudo: required
-dist: trusty
 node_js:
-- 6
+- 8
 cache:
   directories:
   - node_modules
+addons:
+  apt:
+    packages:
+    - libcairo2-dev
+    - libpango1.0-dev
+    - libssl-dev
+    - libjpeg62-dev
+    - libgif-dev
 install:
-- sudo apt-get update && sudo apt-get install -y libcairo2-dev libpango1.0-dev libssl-dev libjpeg62-dev libgif-dev pkg-config
-- npm install canvas@1.6.11
 - npm --production=false install
 - npm --production=false update
+- npm install --no-save canvas@1.6.11
 before_deploy:
 - npm --no-git-tag-version version 0.2.0-prerelease.$(date +%Y%m%d%H%M%S)
 - git config --global user.email $(git log --pretty=format:"%ae" -n1)