error Could not find i18n-0.7.0 in any of the sources

Try:

bin/bundle install

Solves the problem ;)

I solved the problem.

The problem was, I upgraded the Rails version but I did not upgrade the bin/ folder.

So, to do that, I had to run the following command, and override everything:

$ bundle exec rake rails:update:bin

Thanks.

Earlier version was i18n --version 0.6.1

Issue got resolved using the below command.

sudo gem install i18n --version 0.7