New style for drop-down field trigger
Merge branch 'master' of https://github.com/Financial-Times/o-ft-forms into update-select-trigger-style

Conflicts:
	src/scss/_variables.scss
Remove arrow backdrop

This allows us to simply markup and styles
Separate placeholders with commas
Merge branch 'master' of https://github.com/Financial-Times/o-ft-forms into update-select-trigger-style

Conflicts:
	src/scss/fields.scss
Merge pull request #29 from Financial-Times/update-select-trigger-style

New style for drop-down field trigger