Update project dependencies

[pedro-victor]

• Mongoose: 4.12 -> 5.1

• ESLint: 4.4 -> 4.19

• Mockgoose: dropped in favor of mongodb-memory-server

[pedro-victor]

This is my own version of rest and even though it passes the tests locally, it doesn't on TravisCI. I'll try to fix that another time.

[diegohaz]

Thank you for taking the time to work on this, @pedro-victor. I think the problem with Travis may be related to the Node version.

[pedro-victor]

Yes and it's definitely not that simple. I checked in my machine and I'm also not able to run npm test running Node v4-v6.

What do you think about upgrading Node requirements to version 8+? Since it's used only by brand new projects, I don't think that it would be such a bad idea.

I'll test again with upgraded versions, just in case.

[diegohaz]

Doesn't it work with v7 either?

Anyway, I'm ok with upgrading Node version.

[pedro-victor]

I suggested v8 because that's the one I use. 😄

[coveralls]

Coverage remained the same at 100.0% when pulling 03629a2 on pedro-victor:master into 4a6c3d5 on diegohaz:master.

[pedro-victor]

What I've done so far:

• Mongoose: upgraded 4.12 -> 5.1
• ESLint: upgraded 4.4 -> 4.19
• Mockgoose: dropped in favor of mongodb-memory-server for improved parallel testing support
• NSP: dropped because it is complaining about loadash's security flaw but its dependency path (generator-rest@0.12.0 > *yeoman-generator@0.24.1* > html-wiring@1.2.0 > cheerio@0.19.0 > lodash@3.10.1) is not straightforward to eliminate
• Node versions: eliminated support for Node v4 and v5 (translated as removing them from TravisCI) and added support for v7, v8 and v9 (also maintaining v6).

My suggestion is: merge this PR so we can benefit from upgraded versions and, as soon as we are able to upgrade yeoman-generator to v2, we add NSP back. @diegohaz what do you think?

[diegohaz]

Thank you very much, @pedro-victor. 😊