Add shrinkwrap back into nsp check task

[DonutEspresso]

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A recent release of nsp caused nsp's internal dev dependencies to be included as part of the nsp check. This is a bug on nsp's part:
nodesecurity/nsp#185

We should revert #1482 once a new nsp version is released.

[hekike]

nsp finds vulnerabilities in the dependency tree without shrinkwrap if we have a package-lock.json file. Shouldn't we add package-lock.json to restify instead of reverting #1482?

With package-lock.json file:

$ make nsp
(+) 1 vulnerabilities found
┌───────────────┬─────────────────────────────────────────────────────────────────┐
│               │ Regular Expression Denial of Service                            │
├───────────────┼─────────────────────────────────────────────────────────────────┤
│ Name          │ debug                                                           │
├───────────────┼─────────────────────────────────────────────────────────────────┤
│ CVSS          │ 3.7 (Low)                                                       │
├───────────────┼─────────────────────────────────────────────────────────────────┤
│ Installed     │ 2.6.8                                                           │
├───────────────┼─────────────────────────────────────────────────────────────────┤
│ Vulnerable    │ <= 2.6.8 || >= 3.0.0 <= 3.0.1                                   │
├───────────────┼─────────────────────────────────────────────────────────────────┤
│ Patched       │ >= 2.6.9 < 3.0.0 || >= 3.1.0                                    │
├───────────────┼─────────────────────────────────────────────────────────────────┤
│ Path          │ restify@6.0.1 > spdy@3.4.7 > debug@2.6.8                        │
├───────────────┼─────────────────────────────────────────────────────────────────┤
│ More Info     │ https://nodesecurity.io/advisories/534                          │
└───────────────┴─────────────────────────────────────────────────────────────────┘

[hekike]

Related to: #1477