added rename level

levels/rename.rb

@@ -0,0 +1,16 @@
+difficulty 3
+
+description "We have a file called oldFile.txt. We want to rename it to newFile.txt and stage this change."
+
+setup do
+    repo.init
+    FileUtils.touch("oldFile.txt")
+end
+
+solution do
+    repo.status["oldFile.txt"].type == "D" && repo.status["newFile.txt"].type == "A" && repo.status["oldFile.txt"].stage.nil?
+end
+
+hint do
+    puts "Take a look at `git mv`"
+end

lib/githug/level.rb

@@ -6,7 +6,7 @@ class Level
               "clone_to_folder", "ignore", "status", "rm", "rm_cached", "log",
               "commit_ammend", "reset", "checkout_file", "remote", "remote_url",
               "remote_add", "diff", "blame", "branch", "checkout", "merge",
-              "contribute"]
+              "rename", "contribute"]
 
     attr_accessor :level_no, :level_path