Upgrading from 0.6.0 to 0.7.0 fails: "ChomeChromeStorage.java already exists!"

[Haemp]

I get this error when upgrading with cca 0.7:

## Updating plugins based on manifest.json
## Running Cordova Command: plugin add cordova-plugin-background-app cordova-plugin-blob-constructor-polyfill cordova-plugin-chrome-apps-alarms cordova-plugin-chrome-apps-bootstrap@2 cordova-plugin-chrome-apps-common cordova-plugin-chrome-apps-filesystem cordova-plugin-chrome-apps-i18n@2 cordova-plugin-chrome-apps-identity cordova-plugin-chrome-apps-navigation@1 cordova-plugin-chrome-apps-notifications cordova-plugin-chrome-apps-runtime cordova-plugin-chrome-apps-storage cordova-plugin-crosswalk-webview@1 cordova-plugin-customevent-polyfill cordova-plugin-file cordova-plugin-inappbrowser cordova-plugin-network-information cordova-plugin-statusbar cordova-plugin-whitelist cordova-plugin-xhr-blob-polyfill
npm http GET https://registry.npmjs.org/cordova-plugin-background-app
npm http 304 https://registry.npmjs.org/cordova-plugin-background-app
npm http GET https://registry.npmjs.org/cordova-plugin-blob-constructor-polyfill
npm http 304 https://registry.npmjs.org/cordova-plugin-blob-constructor-polyfill
npm http GET https://registry.npmjs.org/cordova-plugin-chrome-apps-alarms
npm http 304 https://registry.npmjs.org/cordova-plugin-chrome-apps-alarms
npm http GET https://registry.npmjs.org/cordova-plugin-chrome-apps-common
npm http 304 https://registry.npmjs.org/cordova-plugin-chrome-apps-common
npm http GET https://registry.npmjs.org/cordova-plugin-chrome-apps-storage
npm http 304 https://registry.npmjs.org/cordova-plugin-chrome-apps-storage

/usr/local/lib/node_modules/cca/node_modules/cordova/node_modules/cordova-lib/node_modules/npm/node_modules/lockfile/lockfile.js:46
      throw er
            ^
Error: Uh oh!
"/path/to/my/project/platforms/android/src/org/chromium/ChromeStorage.java" already exists!

• Tried removing the android platform and adding it again - failed
• Tried removing both the platforms folder and the plugins folder then doing an upgrade - succeeded.