chore: drop contributors from multiple places (#241)

Author: JustinBeckwith

handwritten/datastore/.mailmap

@@ -28,28 +28,6 @@
     "google datastore",
     "datastore"
   ],
-  "contributors": [
-    "Ace Nassri <anassri@google.com>",
-    "Alexander Fenster <github@fenster.name>",
-    "Ali Ijaz Sheikh <ofrobots@google.com>",
-    "Dave Gramlich <callmehiphop@gmail.com>",
-    "Dominic Kramer <DominicDKramer@google.com>",
-    "Eric Uldall <ericuldall@gmail.com>",
-    "Geoffrey Gowan <geoffrey.gowan@gmail.com>",
-    "Jason Dobry <jdobry@google.com>",
-    "Jun Mukai <mukai@google.com>",
-    "Luke Sneeringer <luke@sneeringer.com>",
-    "Luke Sneeringer <lukesneeringer@google.com>",
-    "Patrick Costello <pcostello@google.com>",
-    "Philip Irri <philip@irri.se>",
-    "Song Wang <songwang@google.com>",
-    "Stephen Sawchuk <sawchuk@gmail.com>",
-    "Tim Swast <swast@google.com>",
-    "Walter Poupore <WalterHub@users.noreply.github.com>",
-    "antoine beauᵛᵃᴵˢ⁻lacᵃˢˢᵉ <beaulac@users.noreply.github.com>",
-    "greenkeeper[bot] <greenkeeper[bot]@users.noreply.github.com>",
-    "tcrognon <tcrognon@gmail.com>"
-  ],
   "scripts": {
     "docs": "jsdoc -c .jsdoc.js",
     "generate-scaffolding": "repo-tools generate all && repo-tools generate lib_samples_readme -l samples/ --config ../.cloud-repo-tools.json",