.travis.yml in geo_concerns-0.0.6 vs .travis.yml in geo_concerns-0.0.7

@@ -1,12 +1,18 @@
 language: ruby
 sudo: true
 rvm:
-  - 2.3.0
+  - 2.2.2 # oldest version supported by Rails 5
+  - 2.3.1 # latest release
 env:
   global:
   - NOKOGIRI_USE_SYSTEM_LIBRARIES=true
   - MAPNIK_VERSION="2.3"
+  matrix:
+    - RAILS_VERSION=4.2.7
+      RDF_VERSION=1.99.1
+    - RAILS_VERSION=5.0.0
+      RDF_VERSION=2.1.0
 before_install:
  - sudo apt-add-repository --yes ppa:mapnik/nightly-${MAPNIK_VERSION}
  - sudo apt-get update -y
 install:
  - sudo apt-get -y install wget build-essential make libmapnik=${MAPNIK_VERSION}* mapnik-utils=${MAPNIK_VERSION}* libmapnik-dev=${MAPNIK_VERSION}* mapnik-input-plugin*=${MAPNIK_VERSION}*