Gemfile in data_miner-2.0.3 vs Gemfile in data_miner-2.1.0

@@ -8,9 +8,10 @@
 gem 'minitest-reporters'
 gem 'mysql2'
 gem 'rake'
 gem 'yard'
 gem 'earth'
+gem 'lock_method'
 if RUBY_VERSION >= '1.9'
   gem 'unicode_utils'
 end
 # if RUBY_VERSION >= '1.9'
 #  gem 'ruby-debug19' # replace with debugger?