Replaces libxml with Nokogiri (#375)

* Replaces libxml with Nokogiri

Nokogiri has much wider adoption with Ruby users than libxml.
Some developers were having trouble with libxml installation.
libxml doesn't work on JRuby, but Nokogiri will.
The API doesn't change.

Bonus
The unused `indent` argument to `TwiML` has been removed.

* Fixes up support for JRuby.

Adds jruby to Travis CI config.

* Specify jruby that exists on Travis

* Whitespace removal when code was generated

.travis.yml

@@ -10,6 +10,7 @@ rvm:
   - 2.2.0
   - 2.1
   - 2.0.0
+  - jruby-9.1.9.0
 
 matrix:
   fast_finish: true

lib/twilio-ruby.rb

@@ -1,6 +1,6 @@
 require 'net/http'
 require 'net/https'
-require 'libxml'
+require 'nokogiri'
 require 'cgi'
 require 'openssl'
 require 'base64'

lib/twilio-ruby/twiml/twiml.rb

@@ -1,4 +1,4 @@
-require 'libxml'
+require 'nokogiri'
 
 ##
 # This code was generated by
@@ -11,11 +11,10 @@ module TwiML
     class TwiMLError < StandardError; end
 
     class TwiML
-        attr_accessor :name, :indent
+        attr_accessor :name
 
-        def initialize(indent: false, **keyword_args)
+        def initialize(**keyword_args)
           @name = self.class.name.split('::').last
-          @indent = indent
           @value = nil
           @verbs = []
           @attrs = {}
@@ -35,17 +34,18 @@ def self.to_lower_camel_case(symbol)
         end
 
         def to_s(xml_declaration = true)
-          xml = self.xml.to_s(indent: indent)
-
+          opts = { encoding: 'UTF-8', indent: 0 }
+          document = Nokogiri::XML::Document.new
+          xml = self.xml(document).to_xml(opts).gsub(/\n/, '')
           return ('<?xml version="1.0" encoding="UTF-8"?>' + xml) if xml_declaration
           xml
         end
 
-        def xml
+        def xml(document)
           # create XML element
           value = (@value.is_a?(String) or @value == nil) ? @value : JSON.generate(@value)
-          elem = LibXML::XML::Node.new(@name, value)
-
+          elem = Nokogiri::XML::Node.new(@name, document)
+          elem.content = value
           # set element attributes
           keys = @attrs.keys.sort
           keys.each do |key|
@@ -56,7 +56,7 @@ def xml
           end
 
           @verbs.each do |verb|
-            elem << verb.xml
+            elem << verb.xml(document)
           end
 
           elem

twilio-ruby.gemspec

@@ -24,10 +24,10 @@ Gem::Specification.new do |spec|
   spec.extra_rdoc_files = ['README.md', 'LICENSE.md']
   spec.rdoc_options = ['--line-numbers', '--inline-source', '--title', 'twilio-ruby', '--main', 'README.md']
 
-  spec.add_dependency('libxml-ruby', '>= 2.0', '< 4.0')
+  spec.add_dependency('nokogiri', '>= 1.6', '< 2.0')
   spec.add_dependency('jwt', '~> 1.5')
   spec.add_dependency('faraday', '~>0.9')
-  spec.add_dependency('jruby-openssl') if RUBY_PLATFORM == 'java'
+  spec.add_dependency('jruby-openssl', '>= 0.9.6') if RUBY_PLATFORM == 'java'
   # Workaround for RBX <= 2.2.1, should be fixed in next version
   spec.add_dependency('rubysl') if defined?(RUBY_ENGINE) && RUBY_ENGINE == 'rbx'