Update dependencies. Only log that the license has updated when it

actually has and add instructions to commit it.

package.json

@@ -73,23 +73,23 @@
     "@types/micromatch": "^3.1.0",
     "@types/minimist": "^1.2.0",
     "acorn-import-meta": "^1.0.0",
-    "acorn-jsx": "^5.0.2",
+    "acorn-jsx": "^5.1.0",
     "acorn-walk": "^7.0.0",
     "buble": "^0.19.8",
     "chokidar": "^2.1.8",
     "codecov": "^3.6.1",
     "console-group": "^0.3.3",
-    "core-js": "^3.2.1",
+    "core-js": "^3.3.2",
     "cross-os": "^1.3.0",
     "date-time": "^3.1.0",
     "es5-shim": "^4.5.13",
     "es6-shim": "^0.35.5",
     "eslint": "^6.5.1",
     "eslint-plugin-import": "^2.18.2",
-    "execa": "^2.1.0",
+    "execa": "^3.1.0",
     "fixturify": "^1.2.0",
     "hash.js": "^1.1.7",
-    "husky": "^3.0.8",
+    "husky": "^3.0.9",
     "is-reference": "^1.1.4",
     "lint-staged": "^9.4.2",
     "locate-character": "^2.0.5",
@@ -104,7 +104,7 @@
     "pretty-ms": "^5.0.0",
     "require-relative": "^0.8.7",
     "requirejs": "^2.3.6",
-    "rollup": "^1.23.1",
+    "rollup": "^1.24.0",
     "rollup-plugin-alias": "^2.0.1",
     "rollup-plugin-buble": "^0.19.8",
     "rollup-plugin-commonjs": "^10.1.0",
@@ -122,8 +122,8 @@
     "source-map": "^0.6.1",
     "source-map-support": "^0.5.13",
     "sourcemap-codec": "^1.4.6",
-    "systemjs": "^6.1.3",
-    "terser": "^4.3.8",
+    "systemjs": "^6.1.4",
+    "terser": "^4.3.9",
     "tslib": "^1.10.0",
     "tslint": "^5.20.0",
     "turbocolor": "^2.6.1",

rollup.config.js

@@ -95,18 +95,20 @@ function generateLicenseFile(dependencies) {
 			return text;
 		})
 		.join('\n---------------------------------------\n\n');
-	fs.writeFileSync(
-		'LICENSE.md',
+	const licenseText =
 		`# Rollup core license\n` +
-			`Rollup is released under the MIT license:\n\n` +
-			coreLicense +
-			`\n# Licenses of bundled dependencies\n` +
-			`The published Rollup artifact additionally contains code with the following licenses:\n` +
-			`${Array.from(licenses).join(', ')}\n\n` +
-			`# Bundled dependencies:\n` +
-			dependencyLicenseTexts
-	);
-	console.log('LICENSE.md updated.');
+		`Rollup is released under the MIT license:\n\n` +
+		coreLicense +
+		`\n# Licenses of bundled dependencies\n` +
+		`The published Rollup artifact additionally contains code with the following licenses:\n` +
+		`${Array.from(licenses).join(', ')}\n\n` +
+		`# Bundled dependencies:\n` +
+		dependencyLicenseTexts;
+	const existingLicenseText = fs.readFileSync('LICENSE.md', 'utf8');
+	if (existingLicenseText !== licenseText) {
+		fs.writeFileSync('LICENSE.md', licenseText);
+		console.warn('LICENSE.md updated. You should commit the updated file.');
+	}
 }
 
 const expectedAcornImport = "import acorn__default, { Parser } from 'acorn';";