Fix exclude_hostmanager typo in README
Fix exclude_hostmanager typo in README

This change updates `README` so that the `exclude_hostmanager` property
for `tomcat_install` is written correctly (removed `-`).

Lianping/tomcat,Lianping/tomcat,yakara-ltd/tomcat,Lianping/tomcat,nickptrvc/tomcat,chef-cookbooks/tomcat,nickptrvc/tomcat,yakara-ltd/tomcat,GannettDigital/chef-tomcat,GannettDigital/chef-tomcat,chef-cookbooks/tomcat,opscode-cookbooks/tomcat,chef-cookbooks/tomcat,opscode-cookbooks/tomcat,yakara-ltd/tomcat,GannettDigital/chef-tomcat,nickptrvc/tomcat,opscode-cookbooks/tomcat