Revert "update karma and webpack-stream packages (prebid#3966)" (preb…

…id#4003)

This reverts commit 6399ab1.

package.json

@@ -58,7 +58,7 @@
  "is-docker": "^1.1.0",
  "istanbul": "^0.4.5",
  "istanbul-instrumenter-loader": "^3.0.0",
- "karma": "^4.1.0",
+ "karma": "^3.1.3",
  "karma-babel-preprocessor": "^6.0.1",
  "karma-browserstack-launcher": "^1.3.0",
  "karma-chai": "^0.1.0",
@@ -91,7 +91,7 @@
  "webdriverio": "^4.13.2",
  "webpack": "^3.0.0",
  "webpack-bundle-analyzer": "^3.3.2",
- "webpack-stream": "^5.2.1",
+ "webpack-stream": "^3.2.0",
  "yargs": "^1.3.1"
  },
  "dependencies": {