Update Closure Compiler to v20200204

This commit also adjusts the method for checking versions for Closure
Compiler. The GitHub repository does not have the latest release
correctly tagged, so I switched to a regular expression linked to the
releases page.

README.md

 
 Current programs:
 
-- [Closure Compiler](https://developers.google.com/closure/compiler/) v20200112 ([GitHub releases](https://github.com/google/closure-compiler/releases))
+- [Closure Compiler](https://developers.google.com/closure/compiler/) v20200204 ([GitHub releases](https://github.com/google/closure-compiler/releases))
 - [Dual Key Remap](https://github.com/ililim/dual-key-remap) v0.4 ([GitHub releases](https://github.com/ililim/dual-key-remap/releases))
 - [Go Replace](https://github.com/piranha/goreplace) v2.5 ([GitHub releases](https://github.com/piranha/goreplace/releases))
 - [Google Play Music Desktop Player](https://www.googleplaymusicdesktopplayer.com/) v4.7.1 ([GitHub releases](https://github.com/MarshallOfSound/Google-Play-Music-Desktop-Player-UNOFFICIAL-/releases))

bucket/closure-compiler.json

 {
 	"homepage": "https://developers.google.com/closure/compiler/",
 	"description": "The Closure Compiler is a tool for making JavaScript download and run faster. Instead of compiling from a source language to machine code, it compiles from JavaScript to better JavaScript.",
-	"version": "20200112",
+	"version": "20200204",
 	"license": "Apache-2.0",
-	"url": "https://dl.google.com/closure-compiler/compiler-20200112.zip",
-	"hash": "sha256:EC2FD8BEB15EC8CAF9D18ED803F0A350E6FCD8DC8B397D6D64ECE331994D86EA",
+	"url": "https://dl.google.com/closure-compiler/compiler-20200204.zip",
+	"hash": "sha256:D5F3182D80958A63D500D60CA1CA3695AB1C8CD8D4CBA7DA59BA4016D23F2B0B",
 	"bin": [
 		[
-			"closure-compiler-v20200112.jar",
+			"closure-compiler-v20200204.jar",
 			"closure-compiler"
 		]
 	],
 	"checkver": {
-		"github": "https://github.com/google/closure-compiler"
+		"url": "https://github.com/google/closure-compiler/releases",
+		"regex": "v([\\d]{8})"
 	}
 }