[ruby/tempfile] Expose Tempfile::VERSION

https://github.com/ruby/tempfile/commit/6aa1f37dc4

lib/tempfile.gemspec

@@ -1,6 +1,13 @@
+name = File.basename(__FILE__, ".gemspec")
+version = ["lib", Array.new(name.count("-")+1).join("/")].find do |dir|
+  break File.foreach(File.join(__dir__, dir, "#{name.tr('-', '/')}.rb")) do |line|
+    /^\s*VERSION\s*=\s*"(.*)"/ =~ line and break $1
+  end rescue nil
+end
+
 Gem::Specification.new do |spec|
-  spec.name          = "tempfile"
-  spec.version       = "0.1.3"
+  spec.name          = name
+  spec.version       = version
   spec.authors       = ["Yukihiro Matsumoto"]
   spec.email         = ["matz@ruby-lang.org"]
 

lib/tempfile.rb

@@ -88,6 +88,8 @@ require 'tmpdir'
 # mutex.
 class Tempfile < DelegateClass(File)
 
+  VERSION = "0.1.3"
+
   # Creates a file in the underlying file system;
   # returns a new \Tempfile object based on that file.
   #