Main for loop never terminates for parse!(r, p, Vector{UInt8}("Some-Header:"))

[samoconnor]

The main for loop in parse!() never terminates when the last parser input is fragmented so that the last character in the input bytes is the : at the end of a header.

i.e. If the parser will lock up if the request data is fragmented so that the first call to readavailable(socket) returns "HTTP/1.1 200 OK\r\nDate:".

PR #124 adds a test that parses 1 byte at a time to demonstrate the problem and adds a loop invariant @assert to the for loop to stop in looping forever.

julia> HTTP.parse(HTTP.Response, "HTTP/1.1 200 OK\r\nDate:")
ERROR: AssertionError: p > old_p