[ruby/tempfile] Bump version to 0.1.3

https://github.com/ruby/tempfile/commit/99dc1f7058

lib/tempfile.gemspec

@@ -1,6 +1,6 @@
 Gem::Specification.new do |spec|
   spec.name          = "tempfile"
-  spec.version       = "0.1.2"
+  spec.version       = "0.1.3"
   spec.authors       = ["Yukihiro Matsumoto"]
   spec.email         = ["matz@ruby-lang.org"]