Fix method rename in the latest versions of airbrake - Closes #444

[dmathieu]

Since airbrake/airbrake@8768b1c, BacktraceLine#method has been renamed into BacktraceLine#method_name, therefore breaking errbit for people using the latest versions of the notifier.

This fixes it.

[shingara]

Why not just alias method_name= by method=

alias :method_name= :method=

I think it's enought to work and didn't break compatibility. Because this commit break all old airbrake gem and delete all error doing this this commit.

I did not agree to this Pull request.

[dmathieu]

The usage of method is not a good idea, as the method is already implemented by ruby.
I don't mind aliasing :method to :method_name, for old notifiers compatibility.
But as it's clearly not a good idea to keep it in the long term, we shouldn't just alias.

[shingara]

agree about the long term. But we need alias :method= and :method_name= in your commit and do a migration to be a good PR.

[ndbroadbent]

I agree that alias :method= :method_name= is necessary, otherwise error reports from the old notifier will cause an error like: Undefined method 'method=' for BacktraceLine

[ndbroadbent]

We will also need to update app/models/backtrace_line_normalizer.rb, lib/tasks/errbit/demo.rake and lib/tasks/errbit/database.rake

[swibs]

@dmathieu Why was this pull request closed?

[dmathieu]

Because I don't have enough time to work on it and I don't want anybody to be prevented to fix this because there's something open.