remove .lgtm file, since the service has been discontinued
remove .lgtm file, since the service has been discontinued

see https://github.com/tldr-pages/tldr/pull/1173#issuecomment-266788990 and https://github.com/lgtmco/lgtm/issues/56 for details
deekim/tldr,deekim/tldr,felixonmars/tldr,felixonmars/tldr,zoisom/tldr,UncommonPleb/tldr,felixonmars/tldr,Phizho/tldr,zoisom/tldr,katekyan/tldr,slash3b/tldr,katekyan/tldr,katekyan/tldr,Phizho/tldr,cptdeka10/tldr,Phizho/tldr,zoisom/tldr,slash3b/tldr,UncommonPleb/tldr,cptdeka10/tldr,UncommonPleb/tldr,slash3b/tldr,deekim/tldr,cptdeka10/tldr