ruby: bump to version 2.1.3

Also add hash file.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/ruby/ruby.hash

@@ -0,0 +1,2 @@
+# From https://www.ruby-lang.org/en/downloads/
+md5	74a37b9ad90e4ea63c0eed32b9d5b18f	ruby-2.1.3.tar.gz

package/ruby/ruby.mk

@@ -5,7 +5,7 @@
 ################################################################################
 
 RUBY_VERSION_MAJOR = 2.1
-RUBY_VERSION = $(RUBY_VERSION_MAJOR).2
+RUBY_VERSION = $(RUBY_VERSION_MAJOR).3
 RUBY_VERSION_EXT = 2.1.0
 RUBY_SITE = http://cache.ruby-lang.org/pub/ruby/$(RUBY_VERSION_MAJOR)
 RUBY_DEPENDENCIES = host-pkgconf host-ruby