Watch doesn't reload on CSS changes

[edward-simpson]

General information

• NodeJS version: 8.12.0
• NPM version: 6.9.0

Problem description

patternlab serve initiates a browsersync watch, and reloads on template file changes, but does not on changes to CSS

Reproduction steps

1. npm run patternlab serve --config ./path-to-patternlab-config.json
2. Make change to template file (triggers reload)
3. Make change to CSS (or gulp recompile css) (does not trigger reload)