Validate ssl peers

Before this patch, ssl peers where not validated unless custom
certificate were provided. This led to less strict security and annoying
warnings from em-http library. See igrigorik/em-http-request#339.

Now we properly take tls_verify_peer option (defaults to true) in
consideration. This should increase security.

Change-Id: I3620aa3de63e20976a204be45bce013d816acc52

.rubocop.yml

@@ -6,8 +6,9 @@ AllCops:
 Layout/LineLength:
   Max: 175
 
+# those metrics should be disabled
 Metrics/AbcSize:
-  Max: 90
+  Max: 92
 
 Metrics/BlockLength:
   Max: 188

lib/consul/async/consul_endpoint.rb

@@ -265,7 +265,8 @@ def _handle_error(http, consul_index)
       def fetch
         options = {
           connect_timeout: 5, # default connection setup timeout
-          inactivity_timeout: conf.wait_duration + 1 + (conf.wait_duration / 16) # default connection inactivity (post-setup) timeout
+          inactivity_timeout: conf.wait_duration + 1 + (conf.wait_duration / 16), # default connection inactivity (post-setup) timeout
+          tls: { verify_peer: conf.tls_verify_peer }
         }
         unless conf.tls_cert_chain.nil?
           options[:tls] = {

lib/consul/async/json_endpoint.rb

@@ -184,6 +184,7 @@ def _handle_error(http)
 
       def fetch
         options = {
+          tls: { verify_peer: conf.tls_verify_peer },
           connect_timeout: 5, # default connection setup timeout
           inactivity_timeout: 60 # default connection inactivity (post-setup) timeout
         }

lib/consul/async/vault_endpoint.rb

@@ -230,6 +230,7 @@ def _handle_error(http)
 
       def fetch
         options = {
+          tls: { verify_peer: conf.tls_verify_peer },
           connect_timeout: 5, # default connection setup timeout
           inactivity_timeout: 1 # default connection inactivity (post-setup) timeout
         }