bugfix: treat Expect header value case-insensitive

Author: tokers

lib/resty/requests/request.lua

@@ -14,6 +14,7 @@ local insert = table.insert
 local concat = table.concat
 local find = string.find
 local sub = string.sub
+local lower = string.lower
 local format = string.format
 local ngx_match = ngx.re.match
 local _M = { _VERSION = "0.2" }
@@ -146,7 +147,7 @@ local function new(method, url, session, config)
 
     local body = prepare(url_parts, session, config)
 
-    local expect = session.headers["expect"] == "100-continue"
+    local expect = lower(session.headers["expect"]) == "100-continue"
 
     local r = {
         method = method,