Bump version number to 1.3.0~alpha1
Bump version number to 1.3.0~alpha1

Reviewed-by: iustinp


apyrgio/ganeti,andir/ganeti,ganeti-github-testing/ganeti-test-1,apyrgio/ganeti,andir/ganeti,bitemyapp/ganeti,grnet/snf-ganeti,andir/ganeti,mbakke/ganeti,grnet/snf-ganeti,onponomarev/ganeti,leshchevds/ganeti,onponomarev/ganeti,leshchevds/ganeti,ganeti/ganeti,mbakke/ganeti,yiannist/ganeti,ganeti/ganeti,leshchevds/ganeti,yiannist/ganeti,bitemyapp/ganeti,ganeti/ganeti,yiannist/ganeti,apyrgio/snf-ganeti,dimara/ganeti,ganeti-github-testing/ganeti-test-1,mbakke/ganeti,apyrgio/snf-ganeti,dimara/ganeti