Do not make rego trace unless --trace flag is passed in (open-policy-…

…agent#556)

* Making tracing functionality optional

Signed-off-by: Sarvar Muminov <[email protected]>

* Adding tests

Signed-off-by: Sarvar Muminov <[email protected]>

* Use Trace variable for `verify` command

Signed-off-by: Sarvar Muminov <[email protected]>

Push images on release

Merge pull request open-policy-agent#448 from Blokje5/fix/bug-in-pars…

…e-command-with-combine-flag

Parse command returns incorrect result with --combined flag.

Merge pull request open-policy-agent#436 from Blokje5/feat/adhere-to-…

…xdg-spec

Support XDG specification