Bug: Ethon adapter fails when response headers are empty

[RKushnir]

When using the Ethon adapter and when the response_headers is an empty string, this code produces nil

httplog/lib/httplog/adapters/ethon.rb

Lines 29 to 31 in 730c301

	# Hard to believe that Ethon wouldn't parse out the headers into
	# an array; probably overlooked it. Anyway, let's do it ourselves:
	headers = response_headers.split(/\r?\n/)[1..-1]

which then causes a crash when calling map on it:

httplog/lib/httplog/adapters/ethon.rb

Line 40 in 730c301

response_headers: headers.map{ |header| header.split(/:\s/) }.to_h,

[trusche]

Hmm. Hard to write a test for, since it takes some doing to send a HTTP response without any headers :) Anyway, this should fix it, can you give it a whirl from master?

[RKushnir]

@trusche Works good, thank you. Could you make a new release?