Bump karma-viewport from 1.0.2 to 1.0.3 in /build

Bumps [karma-viewport](https://github.com/squidfunk/karma-viewport) from 1.0.2 to 1.0.3.
- [Release notes](https://github.com/squidfunk/karma-viewport/releases)
- [Changelog](https://github.com/squidfunk/karma-viewport/blob/master/CHANGELOG)
- [Commits](squidfunk/karma-viewport@1.0.2...1.0.3)

Signed-off-by: dependabot[bot] <support@dependabot.com>

build/package.json

@@ -22,7 +22,7 @@
     "karma-jasmine-sinon": "^1.0.4",
     "karma-junit-reporter": "^1.2.0",
     "karma-phantomjs-launcher": "^1.0.4",
-    "karma-viewport": "^1.0.2",
+    "karma-viewport": "^1.0.3",
     "node-sass": "~4.11.0",
     "phantomjs-prebuilt": "*",
     "sinon": "<= 5.0.7"