Prepare 0.3.0 release
Prepare 0.3.0 release

Arcanemagus/linter,atom-community/linter,simurai/linter-plus,elkeis/linter,UltCombo/linter,DanPurdy/linter,levity/linter,kaeluka/linter,iam4x/linter,JohnMurga/linter,e-jigsaw/Linter,AtomLinter/Linter,blakeembrey/linter,josa42/Linter,mdgriffith/linter,shawninder/linter,steelbrain/linter,AsaAyers/linter