During build phase testing phase is failing on develop branch

[RaduCStefanescu]

During the build of the application (npm run build), the testing phase is failing on develop branch.
The error is the following:

WebpackOptionsValidationError: Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
 - configuration.entry should be one of these:
   object { <key>: string | [string] } | string | [string]
   The entry point(s) of the compilation.
    at webpack (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/webpack/lib/webpack.js:16:9)
    at Plugin (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/karma-webpack/dist/karma-webpack.js:128:16)
    at invoke (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:75:15)
    at Array.instantiate (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:59:20)
    at get (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:48:43)
    at /Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:71:14
    at Array.map (<anonymous>)
    at Array.invoke (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:70:31)
    at Injector.get (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:48:43)
    at instantiatePreprocessor (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/karma/lib/preprocessor.js:50:20)
    at Array.forEach (<anonymous>)
    at createPreprocessor (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/karma/lib/preprocessor.js:68:20)
    at Array.invoke (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:75:15)
    at get (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:48:43)
    at /Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:71:14
    at Array.map (<anonymous>)
21 08 2019 17:40:15.026:ERROR [preprocess]: Can not load "webpack"!
  WebpackOptionsValidationError: Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
 - configuration.entry should be one of these:
   object { <key>: string | [string] } | string | [string]
   The entry point(s) of the compilation.
    at webpack (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/webpack/lib/webpack.js:16:9)
    at Plugin (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/karma-webpack/dist/karma-webpack.js:128:16)
    at invoke (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:75:15)
    at Array.instantiate (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:59:20)
    at get (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:48:43)
    at /Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:71:14
    at Array.map (<anonymous>)
    at Array.invoke (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:70:31)
    at Injector.get (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:48:43)
    at instantiatePreprocessor (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/karma/lib/preprocessor.js:50:20)
    at Array.forEach (<anonymous>)
    at createPreprocessor (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/karma/lib/preprocessor.js:68:20)
    at Array.invoke (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:75:15)
    at get (/Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:48:43)
    at /Users/radustefanescu/Code4Romania/repos/monitorizare-vot/monitorizare-vot-votanti-client/node_modules/di/lib/injector.js:71:14
    at Array.map (<anonymous>)

This issue might be related with the upgrade of karma dependencies.