excon.rb

# Excon exposes defaults for injecting configuration parameters
Excon.defaults[:mock] = true 
Excon.defaults.delete(:mock)

# Excon stubbing
# first parameter - Hash of expected request attributes (all are optional)
# second parameter - Hash of response attributes
# if second parameter is omitted, a block can be provided a Proc object
Excon.stub({ method: :post, path: exp_path, headers: exp_headers, query: exp_query, body: exp_body }, { status: 200 })

# Or, just use webmock directly

stub_request(:post, url).with(body: "", headers: {}).to_return(status: 200, body: "")