Checking configuration before running the test

[Andres710]

The test gets an error and fails automatically if the percentages for each type of event do not add up to 100. Currently, this error is detected during Cypress execution and it is time consuming to wait for Cypress to start and consecutively fail each time that the configuration is wrong. The validation of this values could be done before running Cypress to improve performance and give the user a clearer message of why the test wasn't executed as expected.