fix typo in readme composer.json example
fix typo in readme composer.json example

cckakhandki/Behat-Html-Formatter,arminkhoshbin/BehatHtmlFormatterPlugin,pdaoust/BehatHtmlFormatterPlugin,rn0/BehatHtmlFormatterPlugin,fonsecas72/BehatHtmlFormatterPlugin,dutchiexl/BehatHtmlFormatterPlugin,arminkhoshbin/BehatHtmlFormatterPlugin,pdaoust/BehatHtmlFormatterPlugin,rn0/BehatHtmlFormatterPlugin,dutchiexl/BehatHtmlFormatterPlugin,fonsecas72/BehatHtmlFormatterPlugin,cckakhandki/Behat-Html-Formatter