replaced reactour by introJs-react

[disha1202]

Fixes: #142

[llaske]

Good start @disha1202. There are few issues:

• [x] Buttons are not localized

• [x] Once launched the tutorial restart forever on each click on a button

• [x] On template screen the popup has only one button

• [x] A scrollbar appear on the create exercise popup

[disha1202]

Hi @llaske, Thanks for reviewing. I have fixed the above mentioned issues. Please take a look.

[llaske]

@disha1202 nice but there are some errors when clicking on Next button in some screens:

or

[disha1202]

@disha1202 nice but there are some errors when clicking on Next button in some screens:

or

Ohh my bad, In introJs if there is only one step in a tutorial it displays only one button. To fix this and make the UI consistent, I have introduced an empty step object in tutorials which contain only a single step and disabled both the buttons in onBeforeChange event in introJs. This error might be because of that.

[disha1202]

@llaske updated the condition. It should be working fine now. Please take a look.

[llaske]

Thanks @disha1202 . Good job.