deps: upgrade npm to 2.7.4

[othiym23]

This release is mostly bug fixes, including:

• fe1bc38
  #7672 [email protected]:
  Fix client-side certificate handling by correcting property name.
  (@atamon)
• 89ce829
  #7630 [email protected]: Part
  3 of ensuring that GitHub shorthand is handled consistently.
  (@othiym23)
• 63313eb
  #7630
  [email protected]: Part 2 of ensuring that GitHub shorthand
  is handled consistently. (@othiym23)
• 3ed41bf
  #7630 [email protected]: Part
  1 of ensuring that GitHub shorthand is handled consistently.
  (@othiym23)

...but it also includes 2.7.1, 2.7.2, and 2.7.3, which have their own release notes:

• https://github.com/npm/npm/releases/tag/v2.7.1
• https://github.com/npm/npm/releases/tag/v2.7.2
• https://github.com/npm/npm/releases/tag/v2.7.3
• https://github.com/npm/npm/releases/tag/v2.7.4

[misterdjules]

Thank you, landed in 2704c62 👍