README tweak - use wget instead of curl
README tweak - use wget instead of curl

curl is missing from a plain install of ubuntu 16.04
sillsdev/web-cat,ermshiperete/web-languageforge,sillsdev/web-cat,ermshiperete/web-languageforge,sillsdev/web-cat,ermshiperete/web-languageforge,ermshiperete/web-languageforge,ermshiperete/web-languageforge,ermshiperete/web-languageforge,sillsdev/web-scriptureforge,sillsdev/web-cat,sillsdev/web-scriptureforge,sillsdev/web-scriptureforge,sillsdev/web-scriptureforge,ermshiperete/web-languageforge,sillsdev/web-scriptureforge,sillsdev/web-cat,sillsdev/web-scriptureforge,sillsdev/web-cat,sillsdev/web-scriptureforge,sillsdev/web-scriptureforge,sillsdev/web-cat,sillsdev/web-cat,ermshiperete/web-languageforge