[Proposal] Requiring Go 1.2 across the board

[David Cheney]

Hello,

This is a proposal that we raise the minimum Go spec from Go 1.1 to Go 1.2.

Motivation:

* Now that T is out, we have to support Juju on two series (Precise
and Trusty[1]) with two compilers, gc and gccgo.
* gccgo-4.9, which is version we using in trusty, supports the Go 1.2 spec
* gc-1.1.2 which is available in a ppa for precise, obviously supports Go 1.1
* gc-1.2.1 is the shipping compiler on Trusty, it supports Go 1.2

So now we have three compilers, two versions of gc, and one of gccgo.

We are in the situation where code written for gccgo under T on ppc64
or armv8 will not pass the bot running Go 1.1.1.

For this reason I would like to reduce this matrix.

Recommendation:

* Get the trusty compiler into a backport ppa for precise[1]
* Upgrade the bot to use that compiler, raising the minimum compiler
spec to 1.2 across the board

Thoughts / Discussion / Spoiled fruit ?

Dave

[1] I am ignoring the intermediate, non LTS series', as there are no
charms for them, nor do CTS offer support for them. If this is
unacceptable, anything which applies to Precise wrt. backports, also
applies to Q, R and S.