Cleanup Travis config

Author: jeroen

.travis.yml

@@ -1,12 +1,21 @@
 language: R
 cache: packages
-sudo: true
-dist: trusty
 warnings_are_errors: false
+
 r:
   - devel
   - oldrel
   - release
+  
+addons:
+  apt:
+    sources:
+      - sourceline: 'ppa:ubuntugis/ppa'
+    packages:
+      - libudunits2-dev
+      - libproj-dev
+      - libgeos-dev
+      - libgdal-dev
 
 env:
   global:
@@ -21,12 +30,6 @@ env:
 
 before_install:
   - echo "Sys.setenv('plotly_username' = 'cpsievert')" > ~/.Rprofile
-  # sf system dependencies
-  - sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable --yes
-  - sudo apt-get --yes --force-yes update -qq
-  - sudo apt-get install --yes libudunits2-dev libproj-dev libgeos-dev libgdal-dev
-  # make sure R pkgs are upt-to-date
-  - Rscript -e 'update.packages(ask = FALSE)'
 
 before_script:
   - if [[ "$TRAVIS_R_VERSION_STRING" == "release" ]]; then docker run -e GITHUB_PAT=$GITHUB_PAT -e MAPBOX_TOKEN=$MAPBOX_TOKEN -e VMODE="ci" -v $(pwd):/home/plotly --privileged cpsievert/plotly-orca; fi