Merge remote-tracking branch 'bluemonk/master' into 70-contributing-md

# Conflicts:
#	.gitignore

.gitignore

@@ -16,4 +16,5 @@ server.rb
 *.sw?
 /tmp/
 /_yardoc/
-.idea/
\ No newline at end of file
+.idea/
+

Gemfile

 source "https://rubygems.org"
 
 gemspec
+
+group :development do
+  gem 'minitest', '~> 5.8', '>= 5.8.4'
+end

lib/ipaddress/ipv4.rb

@@ -634,20 +634,6 @@ module IPAddress;
       [self.class.new("224.0.0.0/4")].any? {|i| i.include? self}
     end
 
-    #
-    # Checks if an IPv4 address objects belongs
-    # to a multicast network RFC3171
-    #
-    # Example:
-    #
-    #   ip = IPAddress "224.0.0.0/4"
-    #   ip.multicast?
-    #     #=> true
-    #    
-    def multicast?
-      [self.class.new("224.0.0.0/4")].any? {|i| i.include? self}
-    end
-
     #
     # Checks if an IPv4 address objects belongs
     # to a loopback network RFC1122