deps: update dependencies

The new nock wouldn't work if we still had to support Node.js 0.8, but
since the CLI team has dropped support for 0.8, this isn't a problem.

package.json

@@ -11,25 +11,23 @@
     "test": "standard && tap test/*.js"
   },
   "dependencies": {
-    "chownr": "^1.0.1",
-    "concat-stream": "^1.4.6",
-    "graceful-fs": "^4.1.2",
-    "mkdirp": "^0.5.0",
+    "concat-stream": "^1.5.2",
+    "graceful-fs": "^4.1.6",
     "normalize-package-data": "~1.0.1 || ^2.0.0",
     "npm-package-arg": "^3.0.0 || ^4.0.0",
-    "once": "^1.3.0",
-    "request": "^2.47.0",
-    "retry": "^0.8.0",
-    "rimraf": "2",
+    "once": "^1.3.3",
+    "request": "^2.74.0",
+    "retry": "^0.10.0",
     "semver": "2 >=2.2.1 || 3.x || 4 || 5",
     "slide": "^1.1.3"
   },
   "devDependencies": {
-    "negotiator": "^0.4.9",
-    "nock": "^0.56.0",
-    "readable-stream": "^2.0.2",
+    "negotiator": "^0.6.1",
+    "nock": "^8.0.0",
+    "readable-stream": "^2.1.5",
+    "rimraf": "^2.5.4",
     "standard": "^4.0.0",
-    "tap": "^1.2.0"
+    "tap": "^7.0.0"
   },
   "optionalDependencies": {
     "npmlog": "~2.0.0 || ~3.1.0"