Merge branch 'release' into 'master'

Release v0.0.8.

See merge request pubsweet/db-manager!8

package.json

 {
   "name": "@pubsweet/db-manager",
-  "version": "0.0.7",
+  "version": "0.0.8",
   "description": "Provides database management utilities to Pubsweet apps.",
   "main": "src/index.js",
   "scripts": {