Only scalar variables are loaded from test file

[joao-carloto]

For now I'll just block file loading and present the following warning:

"Sorry. The Variables section, of the test file you are loading, seems to contain something other than scalar variables (${...}), defined on a single row. Firerobot GUI currently doesn't support that, so it can't load your test file. To manage your test project, use a proper IDE. FireRobot purpose is just to help you create and export new keywords."