update README with mongodb install info for other Ubuntu distros
update README with mongodb install info for other Ubuntu distros

Flaburgan/diaspora,despora/diaspora,KentShikama/diaspora,Flaburgan/diaspora,geraspora/diaspora,geraspora/diaspora,Muhannes/diaspora,spixi/diaspora,despora/diaspora,geraspora/diaspora,SuperTux88/diaspora,KentShikama/diaspora,SuperTux88/diaspora,jhass/diaspora,Amadren/diaspora,jhass/diaspora,spixi/diaspora,KentShikama/diaspora,KentShikama/diaspora,SuperTux88/diaspora,Flaburgan/diaspora,diaspora/diaspora,jhass/diaspora,Amadren/diaspora,despora/diaspora,geraspora/diaspora,despora/diaspora,spixi/diaspora,Muhannes/diaspora,diaspora/diaspora,Muhannes/diaspora,diaspora/diaspora,Flaburgan/diaspora,Muhannes/diaspora,jhass/diaspora,diaspora/diaspora,SuperTux88/diaspora,spixi/diaspora,Amadren/diaspora,Amadren/diaspora