fix secure integration spec tagging (elastic#773)

* fix secure integration spec tagging

by default devutils exludes a set of spec tags but that set doesn't
include this plugin's "secure_integration" tag. This PR adds that tag
to the default set of exclusions.

* handle missing ES_VERSION variable

* handle lack of es version in specs

spec/es_spec_helper.rb

@@ -2,6 +2,12 @@
 require 'manticore'
 require 'elasticsearch'
 
+# by default exclude secure_integration tests unless requested
+# normal integration specs are already excluded by devutils' spec helper
+RSpec.configure do |config|
+   config.filter_run_excluding config.exclusion_filter.add(:secure_integration => true)
+end
+
 module ESHelper
   def get_host_port
     "127.0.0.1:9200"
@@ -17,6 +23,10 @@ def self.es_version
 
   def self.es_version_satisfies?(*requirement)
     es_version = RSpec.configuration.filter[:es_version] || ENV['ES_VERSION']
+    if es_version.nil?
+      puts "Info: ES_VERSION environment or 'es_version' tag wasn't set. Returning false to all `es_version_satisfies?` call."
+      return false
+    end
     es_release_version = Gem::Version.new(es_version).release
     Gem::Requirement.new(requirement).satisfied_by?(es_release_version)
   end

spec/integration/outputs/index_spec.rb

@@ -129,7 +129,7 @@
     it_behaves_like("an indexer")
   end
 
-  describe "a secured indexer", :elasticsearch_secure => true do
+  describe "a secured indexer", :secure_integration => true do
     let(:user) { "simpleuser" }
     let(:password) { "abc123" }
     let(:cacert) { "spec/fixtures/test_certs/test.crt" }