Switch to cmd array so we can redact

lib/mrsk/configuration.rb

@@ -38,8 +38,7 @@ class Mrsk::Configuration
   end
 
   def envs
-    parameterize "-e", \
-      { "RAILS_MASTER_KEY" => master_key }.merge(env || {})
+    parameterize "-e", env if env.present?
   end
 
   def labels
@@ -56,6 +55,10 @@ class Mrsk::Configuration
     { user: config.ssh_user || "root", auth_methods: [ "publickey" ] }
   end
 
+  def master_key
+    ENV["RAILS_MASTER_KEY"] || File.read(Rails.root.join("config/master.key"))
+  end
+
   private
     attr_accessor :config
 
@@ -72,8 +75,4 @@ class Mrsk::Configuration
     def parameterize(param, hash)
       hash.collect { |k, v| "#{param} #{k}=#{v}" }.join(" ")
     end
-
-    def master_key
-      ENV["RAILS_MASTER_KEY"] || File.read(Rails.root.join("config/master.key"))
-    end
 end