There are three candidates who have been dropped by their parties in the Nova Scotia election. One Liberal, one NDP, and one PC. The story links (where available) are here:
The actual content of what was said, especially in the third case, is rather tame compared to one might see on the internet.
None of these candidates were in particularly winnable ridings, but it never looks good to drop a candidate.
Regardless, while we do see more and more of this, I am also seeing more and more backlash against it. People who use Twitter as a personal platform will have said many things similar (perhaps, though, not so racist) and will not think that such comments are so extreme. With the stuff Trump says and his use of Twitter, I also think that we will begin to see a growing unwillingness to toss candidates based on statements that are not extreme, and as such, this kind of thing is actually on the way out. Within 20-30 years, it will simply be expected that every candidate running has said something stupid at some point in the past on social media, and no one will care.