Adds Golang 1.3+ instructions to README

Added some documentation to install Golang 1.3+ on Ubuntu since the
project won't build on previous versions.

Signed-off-by: Chris Glass <chris.glass@canonical.com>
Updated README instructions

Points to the LXC PPA instead.

Signed-off-by: Chris Glass <chris.glass@canonical.com>
Merge pull request #84 from chrisglass/fix-readme

Adds Golang 1.3+ instructions to README