12.04 - Unable to locate package when running apt-get

I installed rvm and it tells me I'm missing some packages:

viggy@viggy:~$ rvm requirements
Installing requirements for ubuntu, might require sudo password.
Skipping `apt-get update` make sure your system is up to date.
RVM autolibs is now configured with mode '2' => 'check and stop if missing',

please run `rvm autolibs enable` to let RVM do its job or run and read `rvm autolibs [help]`
or visit https://rvm.io/rvm/autolibs for more information.
Missing required packages: libreadline6-dev, zlib1g-dev, libssl-dev, libyaml-dev, libsqlite3-dev, sqlite3, libxml2-dev, libxslt1-dev, autoconf, libgdbm-dev, libncurses5-dev, automake, libtool, bison, libffi-dev.

So I try to install them but get a ton of unable to locate package errors:

viggy@viggy:~$ sudo apt-get --no-install-recommends install libreadline6-dev, zlib1g-dev, libssl-dev, libyaml-dev, libsqlite3-dev, sqlite3, libxml2-dev, libxslt1-dev, autoconf, libgdbm-dev, libncurses5-dev, automake, libtool, bison, libffi-dev
Reading package lists... Done
Building dependency tree       

Reading state information... Done
E: Unable to locate package libreadline6-dev,
E: Unable to locate package zlib1g-dev,
E: Unable to locate package libssl-dev,
E: Unable to locate package libyaml-dev,
E: Unable to locate package libsqlite3-dev,
E: Unable to locate package sqlite3,
E: Unable to locate package libxml2-dev,
E: Unable to locate package libxslt1-dev,
E: Unable to locate package autoconf,

E: Unable to locate package libgdbm-dev,
E: Unable to locate package libncurses5-dev,
E: Unable to locate package automake,
E: Unable to locate package libtool,
E: Unable to locate package bison,