Tests for Application Challenge page

[x] click on intro tab changes html correctly
[x] click on challenge tab changes html correctly
[x] click on upload tab changes html correctly
[x] display the remaining time correctly
[x] display challenge text correctly
[x] store selected programming language correctly
[x] store "other" programming language correctly
[x] store selected operating system correctly
[x] store "other" operating system correctly
[x] display error message when file is already uploaded
[x] display error message when file is too big
[x] display error message when file has the wrong filetype
[x] display error message when file has wrong filetype and is too big
[x] display uploaded file correctly
[x] delete uploaded file correctly
[x] display correct error messages when every data is left out on submit
[x] display correct error messages when programmin language and OS is selected as "other" but not specified on submit
[x] change html correctly before the response of the backend during submit arrives
[x] change html correctly after successful submit
[x] correctly redirect after error response from backend during submit
[x] display dialog on question mark click
[x] format bytes correctly

ampcc / coding-challenge