fourseven:scss@4.10.0 prevents Meteor upgrade

[tosinek]

Upgrading from 1.8 to 1.9 or 1.10 is not possible due to the scss@4.10 dependency.
I had to remove Bert to proceed with the upgrade.
Although I like Bert, I will probably migrate to Bootstrap toasts :(.

[jirkadev]

I think that bump of scss to 4.12.0 will solve the problem

it worked for me
#57