Remove broken image from README #390

Job	Run time
lint	22s
test (2.1, gems/rails3.gemfile)	21s
test (2.2)	22s
test (2.3)	26s
test (2.4)	24s
test (2.5)	24s
test (2.6)	23s
test (2.6, gems/typhoeus.gemfile, typhoeus)	22s
test (2.6, gems/octoshark.gemfile)	23s
test (2.6, gems/rails3.gemfile, 1.17.3)	26s
test (2.7)	26s
test (2.7, true)	26s
test (3.0)	16s
test (3.0, true)	9s
test (3.0, gems/instruments.gemfile, instruments)	14s
test (3.0, gems/instruments.gemfile, true, instruments)	10s
test (3.0, gems/sidekiq.gemfile, sidekiq_install)	9s
test (3.1)	8s
test (3.2)	11s
	6m 2s

Provide feedback