Add support for cordova installed as a dev dependency

[AssetKid]

Hello,

At the moment, Cordova has to be installed globally for the generator to work

https://github.com/m0dch3n/vue-cli-plugin-cordova/blob/master/generator.js#L8-L13

It is not always possible to install packages globally due to permission restrictions. Is it possible to support Cordova installed as a dev dependencies?

Useful Links

• Introducing npx: an npm package runner
• npm v5.2.0 (2017-07-05)
• Node.js 8.2.0 (upgrade npm to 5.3.0) - deps: upgrade npm to 5.3.0 nodejs/node#14235

[m0dch3n]

@AssetKid feel free to create PR, I'll merge it then

[AssetKid]

I forgot I opened this. I did attempt to make a PR but the solution was not elegant. The cwd (i.e. src-cordova) for the cordova commands and the local dependencies install location (project root) are different.

This means npx cordova commands won't work.

I did have to hard code certain paths in the project I was working on but it was not an elegant solution. I'll close this now.