added tag level

Gemfile

@@ -1,4 +1,4 @@
 source "http://rubygems.org"
 
-# Specify your gem's dependencies in gitscrub.gemspec
+# Specify your gem's dependencies in githug.gemspec
 gemspec

levels/tag.rb

@@ -0,0 +1,18 @@
+difficulty 2
+
+description "We have a git repo and we want to tag the current commit with new_tag."
+
+setup do
+    repo.init
+    FileUtils.touch("somefile.txt")
+    repo.add("somefile.txt")
+    repo.commit_all("Added some file to the repo")
+end
+
+solution do
+    repo.tags.first.name == "new_tag"
+end
+
+hint do
+    puts "Take a look at `git tag`"
+end

lib/githug/level.rb

@@ -4,7 +4,7 @@ class Level
 
     LEVELS = [nil, "init", "add", "commit", "config", "clone",
               "clone_to_folder", "ignore", "status", "rm", "rm_cached", "rename",
-              "log", "commit_ammend", "reset", "checkout_file", "remote",
+              "log", "tag",  "commit_ammend", "reset", "checkout_file", "remote",
               "remote_url", "remote_add", "diff", "blame", "branch", "checkout",
               "merge", "squash", "contribute"]