Typo in file icons.less
There is a typo in the variable on the following line in `icons.less`. The variable is named `@fi-icket-alt`, instead of `@fi-ticket-alt`. [https://github.com/kenangundogan/fontisto/blob/master/less/fontisto/icons.less#L518](https://github.com/kenangundogan/fontisto/blob/master/less/fontisto/icons.less#L518)

The variable is declared here : [https://github.com/kenangundogan/fontisto/blob/master/less/fontisto/variables.less#L529](https://github.com/kenangundogan/fontisto/blob/master/less/fontisto/variables.less#L529)