Move proxy deps to @cypress namespace, use cypress.io urls for tests (#3860)

* debugging-proxy -> @cypress/debugging-proxy

* server: move perf urls to cypress.io, also test http perf

* update low water mark for CI

* server: run perf tests on vanilla chrome proxy first to establish baseline for real tests

* fix tests

packages/https-proxy/package.json

@@ -23,7 +23,7 @@
     "bin-up": "1.1.0",
     "chai": "3.5.0",
     "cross-env": "5.2.0",
-    "debugging-proxy": "1.6.0",
+    "@cypress/debugging-proxy": "1.6.0",
     "request": "2.88.0",
     "request-promise": "4.2.4",
     "sinon": "1.17.7",

packages/https-proxy/test/integration/proxy_spec.coffee

@@ -3,7 +3,7 @@ require("../spec_helper")
 process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0"
 
 _           = require("lodash")
-DebugProxy  = require("debugging-proxy")
+DebugProxy  = require("@cypress/debugging-proxy")
 net         = require("net")
 path        = require("path")
 Promise     = require("bluebird")