Honor credentials on calling Bamboo CI trigger

This improves the Bamboo Service and provides a fix for situations,
where the build trigger won't work, because Bamboo is requiring
authentication also for the trigger GET.

The change now does provide additional HTTP Basic Auth parameters
if user credentials were provided and appends an request parameter
indicating the HTTP Basic Authentication should be used.
This aligns interaction with Bamboo with the other calls this service
executes.
Signed-off-by: Rémy Coutable <remy@rymai.me>

app/models/project_services/bamboo_service.rb

 class BambooService < CiService
-  include HTTParty
-
   prop_accessor :bamboo_url, :build_key, :username, :password
 
   validates :bamboo_url, presence: true, url: true, if: :activated?
@@ -112,8 +110,19 @@ class BambooService < CiService
   def execute(data)
     return unless supported_events.include?(data[:object_kind])
 
-    # Bamboo requires a GET and does not take any data.
+    # Bamboo requires a GET and does take authentification
     url = URI.join(bamboo_url, "/updateAndBuild.action?buildKey=#{build_key}").to_s
-    self.class.get(url, verify: false)
+
+    if username.blank? && password.blank?
+      HTTParty.get(url, verify: false)
+    else
+      url << '&os_authType=basic'
+      auth = {
+        username: username,
+        password: password
+      }
+      HTTParty.get(url, verify: false, basic_auth: auth)
+    end
+
   end
 end