.travis.yml in cloudflare-4.1.2 vs .travis.yml in cloudflare-4.1.3

@@ -1,9 +1,14 @@
 language: ruby
 dist: xenial
 cache: bundler
 
+addons:
+  apt:
+    packages:
+    - squid
+
 matrix:
   include:
     - rvm: 2.4
     - rvm: 2.5
     - rvm: 2.6
@@ -11,9 +16,12 @@
       env: COVERAGE=BriefSummary,Coveralls
     - rvm: jruby-head
       env: JRUBY_OPTS="--debug -X+O"
     - rvm: truffleruby
     - rvm: ruby-head
+    - rvm: 2.6
+      env: CLOUDFLARE_PROXY=http://localhost:3128
+      before_script: sudo service squid start
   allow_failures:
     - rvm: ruby-head
     - rvm: jruby-head
     - rvm: truffleruby