Update dependency gulp-uglify to v1.5.1 - autoclosed

[mend-for-github-com[bot]]

This PR contains the following updates:

Package	Type	Update	Change
gulp-uglify	devDependencies	minor	1.2.0 -> 1.5.1

By merging this PR, the below vulnerabilities will be automatically resolved:

	Severity	CVSS Score	CVE
	High	9.8	CVE-2015-8857
	High	7.5	CVE-2015-8858

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Release Notes

terinjokes/gulp-uglify

### [`v1.5.1`](https://togithub.com/terinjokes/gulp-uglify/compare/v1.4.2...v1.5.1) [Compare Source](https://togithub.com/terinjokes/gulp-uglify/compare/v1.4.2...v1.5.1) ### [`v1.4.2`](https://togithub.com/terinjokes/gulp-uglify/blob/master/CHANGELOG.md#​142) [Compare Source](https://togithub.com/terinjokes/gulp-uglify/compare/v1.4.1...v1.4.2) - Updated UglifyJS to 2.5.0. - CI and dependencies chores. ### [`v1.4.1`](https://togithub.com/terinjokes/gulp-uglify/blob/master/CHANGELOG.md#​141) [Compare Source](https://togithub.com/terinjokes/gulp-uglify/compare/v1.4.0...v1.4.1) - Detect if options is a non-Object and log a warning. Older versions of Node.js did not allow Strings to be passed to `Object.keys` leading to errors and confusion to users following certain tutorials. ### [`v1.4.0`](https://togithub.com/terinjokes/gulp-uglify/blob/master/CHANGELOG.md#​140) [Compare Source](https://togithub.com/terinjokes/gulp-uglify/compare/v1.3.0...v1.4.0) - Deprecated the `preserveComments` option of "some". - Added the `preserveComments` option of "license" that uses [`uglify-save-license`](https://togithub.com/shinnn/uglify-save-license). ### [`v1.3.0`](https://togithub.com/terinjokes/gulp-uglify/blob/master/CHANGELOG.md#​130) [Compare Source](https://togithub.com/terinjokes/gulp-uglify/compare/v1.2.0...v1.3.0) - Updated UglifyJS to 2.4.24. - Streams3 support via through2 dependency update.

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