Bump rails to 4.2.8

[dependabot-preview[bot]]

Bumps rails from 4.2.7 to 4.2.8.

• Commits

I'll automatically resolve any conflicts with this PR as long as you don't alter it yourself.

If you'd like to skip this version, you can just close this PR. If you have any feedback just mention @dependabot in the comments below.

[coveralls]

Coverage remained the same at 92.368% when pulling 4a0e32b41f30ecebd226572684b2b1f47cd0670b on bump/ruby/rails-4.2.8 into de8fe2b71c6d8c31649a67068284bffc21d6f1a3 on master.

[dependabot-preview[bot]]

Superseded by #98.