adding graphite2 1.3.4 to download server

[Martin Hosken]

Dear All,

Please can someone pull the graphite2 source tarball for inclusion in graphite. The new version has shrunk from 8MB to <200K. So life has got a smidgen faster as a result and we've saved a few Joules of energy in the world :)

https://github.com/silnrsi/graphite/releases/download/1.3.4/graphite2-minimal-1.3.4.tgz

TIA,
Yours,
Martin