* flux: ensure git tags are always available
previous `--unshallow` would only run when `--depth 0` was used. If
1--single-branch` was used, then the `.git/shallow` file would not exist
and `--unshallow` would not work.
add v0.6.0 and update dependencies accordingly
update dependencies to match latest flux versions
adds support for python 3
increases precision of czmq version required for older flux versions
adds new lz4 dependency
49c705aebe