Ensure boolean CLI arguments are treated as such

... by properly taking advantage of minimist's built-in features

previously boolean arguments would swallow subsequent positional
arguments (i.e. `--foo bar` erroneously resulted in `{ foo: "bar" }`)

note that we're not using minimist's default for the config file because
that value is set by `lib/config.js` instead, as we want that default to
be the same whether you're using the CLI or the imperative API

Author: moonglum

lib/cli.js

@@ -25,6 +25,7 @@ Options:
 
 module.exports = function parseCLI(argv = process.argv.slice(2), help = HELP) {
 	argv = parseArgs(argv, {
+		boolean: ["watch", "fingerprint", "sourcemaps", "compact"],
 		alias: {
 			c: "config",
 			w: "watch",
@@ -36,14 +37,12 @@ module.exports = function parseCLI(argv = process.argv.slice(2), help = HELP) {
 		abort(help, 0);
 	}
 
-	let options = ["watch", "fingerprint", "sourcemaps", "compact"];
-	options = options.reduce((memo, option) => {
-		let value = argv[option];
-		if(value !== undefined) {
-			memo[option] = value;
-		}
-		return memo;
-	}, {});
+	let options = {
+		watch: argv.watch,
+		fingerprint: argv.fingerprint,
+		sourcemaps: argv.sourcemaps,
+		compact: argv.compact
+	};
 
 	if(options.watch && options.fingerprint) { // for convenience
 		console.error("you might consider disabling fingerprinting in watch " +