Remove devDependencies

[danielpeintner]

node-wot is getting quite heavy with all the dependencies (including devDependencies).

Running npm prune --production should do the job to remove all devDependencies. Anyhow, with lerna it's a bit different and with some hint from here I managed to run sudo lerna exec -- npm prune --production on Linux and it gets me down from more than 500MB to 179MB.
Note: I believe there are still dependencies that are not needed at runtime.

Running the same command on Windows fails with ENOENT error

(node:13264) UnhandledPromiseRejectionWarning: Unhandled promise rejection (reje
ction id: 6): Error: spawn npm ENOENT

[mkovatsc]

I did a clean-up of devDependencies vs dependencies. Due to npm, a development node-wot installation is still very large due to the redundant node_modules. Nothing much to do about this unless we change to something like Yarn.

I created an Issue to investigate Yarn on the Eclipse Issue tracker: eclipse-thingweb/node-wot#15

Closing here.