Allow for a CI_ACCESS_TOKEN ENV var

Author: jhersh

lib/slather/project.rb

@@ -105,7 +105,7 @@ def configure_coverage_service_from_yml
     end
 
     def configure_ci_access_token_from_yml
-      self.ci_access_token ||= (self.class.yml["ci_access_token"] || "")
+      self.ci_access_token ||= (self.class.yml["ci_access_token"] || ENV['CI_ACCESS_TOKEN'])
     end
 
     def coverage_service=(service)