tour: put new packages/imports section in the right place

Author: SethTisue

_tour/named-arguments.md

@@ -7,6 +7,7 @@ discourse: true
 partof: scala-tour
 
 num: 34
+next-page: packages-and-imports
 previous-page: default-parameter-values
 prerequisite-knowledge: function-syntax
 

tutorials/tour/2017-02-25-packages-and-imports.md renamed to _tour/packages-and-imports.md

@@ -1,16 +1,15 @@
 ---
-layout: tutorial
+layout: tour
 title: Packages and Imports
 
-disqus: true
+discourse: true
 
-tutorial: scala-tour
-categories: tour
-num: 4
-next-page:
-previous-page: named-parameters
-prerequisite-knowledge: basics, unified-types, classes
+partof: scala-tour
+
+num: 35
+previous-page: named-arguments
 ---
+
 # Packages and Imports
 Scala uses packages to create namespaces which allow you to modularize programs.