fix(deps): pin dependencies

[renovate]

This PR contains the following updates:

Package	Type	Update	Change	References
babel-cli	dependencies	pin	^6.26.0 -> 6.26.0	homepage, source
babel-core	devDependencies	pin	^6.26.3 -> 6.26.3	homepage, source
babel-preset-es2015	devDependencies	pin	^6.24.1 -> 6.24.1	homepage, source
babel-register	devDependencies	pin	^6.26.0 -> 6.26.0	source
browser-sync	devDependencies	pin	^2.26.3 -> 2.26.3	homepage, source
del	devDependencies	pin	^2.2.2 -> 2.2.2	source
gulp	devDependencies	pin	^3.9.1 -> 3.9.1	homepage, source
gulp-autoprefixer	devDependencies	pin	^3.1.1 -> 3.1.1	source
gulp-babel	devDependencies	pin	^6.1.2 -> 6.1.2	source
gulp-cache	devDependencies	pin	^0.4.2 -> 0.4.6	source
gulp-cssnano	devDependencies	pin	^2.0.0 -> 2.1.3	source
gulp-eslint	devDependencies	pin	^3.0.0 -> 3.0.1	source
gulp-gh-pages	devDependencies	pin	^0.5.4 -> 0.5.4	source
gulp-htmlmin	devDependencies	pin	^3.0.0 -> 3.0.0	source
gulp-if	devDependencies	pin	^2.0.2 -> 2.0.2	source
gulp-imagemin	devDependencies	pin	^3.1.1 -> 3.4.0	source
gulp-jsonminify	devDependencies	pin	^1.1.0 -> 1.1.0	source
gulp-load-plugins	devDependencies	pin	^1.5.0 -> 1.5.0	source
gulp-plumber	devDependencies	pin	^1.2.1 -> 1.2.1	source
gulp-size	devDependencies	pin	^2.1.0 -> 2.1.0	source
gulp-sourcemaps	devDependencies	pin	^2.2.0 -> 2.6.4	source
gulp-uglify	devDependencies	pin	^2.0.0 -> 2.1.2	source
gulp-useref	devDependencies	pin	^3.0.0 -> 3.1.6	source
main-bower-files	devDependencies	pin	^2.5.0 -> 2.13.1	source
run-sequence	devDependencies	pin	^1.2.2 -> 1.2.2	source
wiredep	devDependencies	pin	^4.0.0 -> 4.0.0	source

📌 Important: Renovate will wait until you have merged this Pin PR before creating any upgrade PRs for the affected packages. Add the preset :preserveSemverRanges your config if you instead don't wish to pin dependencies.

---

Renovate configuration

📅 Schedule: At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻️ Rebasing: Whenever PR is stale, or if you modify the PR title to begin with "rebase!".

👻 Immortal: This PR will be recreated if closed unmerged. Get config help if that's undesired.

---

• If you want to rebase/retry this PR, check this box

---

This PR has been generated by Renovate Bot. View repository job log here.