Merge pull request #392 from rubyzip/update-ci

Update supported ruby versions

.travis.yml

@@ -4,10 +4,11 @@ cache: bundler
 rvm:
   - 2.0.0
   - 2.1.10
-  - 2.2.9
-  - 2.3.6
-  - 2.4.3
-  - 2.5.0
+  - 2.2.10
+  - 2.3.8
+  - 2.4.5
+  - 2.5.3
+  - 2.6.0
   - ruby-head
 matrix:
   include:
@@ -24,16 +25,14 @@ matrix:
     - rvm: ruby-head
     - rvm: rbx-3
     - rvm: jruby-head
-    - rvm: jruby
 before_install:
-  - "if $(ruby -e 'exit(RUBY_VERSION >= \"2.3.0\")'); then gem update --system; fi"
-  - "if $(ruby -e 'exit(RUBY_VERSION <  \"2.3.0\")'); then gem update --system 2.7.8; fi"
-  - "if $(ruby -e 'exit(RUBY_VERSION >= \"2.3.0\")'); then gem install bundler; fi" 
-  - "if $(ruby -e 'exit(RUBY_VERSION <  \"2.3.0\")'); then gem install bundler --version 1.17.3; fi"
   - gem --version
 before_script:
   - echo `whereis zip`
   - echo `whereis unzip`
 env:
   global:
     - JRUBY_OPTS="--debug"
+    - COVERALLS_PARALLEL=true
+notifications:
+  webhooks: https://coveralls.io/webhook