Change Travis JRuby to default and allow failures.

Author: gkellogg

.travis.yml

@@ -6,7 +6,7 @@ env:
 rvm:
   - 2.2.5
   - 2.3.1
-  - jruby-9.1.2.0
+  - jruby
   - rbx
 gemfile:
   - Gemfile
@@ -19,3 +19,4 @@ sudo: false
 matrix:
   allow_failures:
     - rvm: rbx
+    - rvm: jruby

Gemfile-pure

@@ -21,7 +21,6 @@ group :development do
 end
 
 group :debug do
-  gem "wirble"
   gem "ruby-debug", platforms: :jruby
   gem "byebug",     platform: :mri
 end