Don't swallow YAML parse errors

[JanStevens]

Hello,

If the YAML file cannot be parsed correctly (for whatever reason) AssetSync should just fail and die. We wasted a day on a type just to find out that AssetSync swallows any errors.

    def yml
      begin
        @yml ||= YAML.load(ERB.new(IO.read(yml_path)).result)[Rails.env] rescue nil || {}
      rescue Psych::SyntaxError
        @yml = {}
      end
    end

But after finding it it worked! (still happy camper)

Regards,

[PikachuEXE]

I find this commit only (with Blame)
06af52e
Not sure what's the reason of that change

Also already got #270 that proposed to NOT rescue the error
But I think I will create another PR to raise custom error with better error message

[PikachuEXE]

Fixed in e0084a2