add a rety option to the step command

[lewismarshall]

This adds flags to allow for commands to be retried with backoff (at this time all commands) but simple.

Regression test

13:44 $ docker run -it --entrypoint /bin/step europe-west2-docker.pkg.dev/appvia-hub/terranetes-executor-step-up/wf-step:1.0.4 --comment=gogo --command=true

=======================================================
GOGO
=======================================================
INFO[0000] successfully executed the step
✔ ~/projects/appvia/terranetes-controller [add-retry-to-step|✚ 2]
13:44 $ docker run -it --entrypoint /bin/step europe-west2-docker.pkg.dev/appvia-hub/terranetes-executor-step-up/wf-step:1.0.4 --comment=gogo --command=false

=======================================================
GOGO
=======================================================
ERRO[0000] command execution failed                      attempt=0 command=0 error="exit status 1"
Error: command failed after 1 attempts: exit status 1
[Error] command failed after 1 attempts: exit status 1
✘-1 ~/projects/appvia/terranetes-controller [add-retry-to-step|✚ 2]

New functionality

13:44 $ docker run -it --entrypoint /bin/step europe-west2-docker.pkg.dev/appvia-hub/terranetes-executor-step-up/wf-step:1.0.4 --comment=gogo --command=false --retry-attempts=3 --retry-min-backoff=3s --retry-max-jitter=5s

=======================================================
GOGO
=======================================================
ERRO[0000] command execution failed                      attempt=0 command=0 error="exit status 1"
INFO[0000] retrying command                              attempt=1 backoff=7.94378454s command=0
ERRO[0007] command execution failed                      attempt=1 command=0 error="exit status 1"
INFO[0007] retrying command                              attempt=2 backoff=3.351980995s command=0
ERRO[0011] command execution failed                      attempt=2 command=0 error="exit status 1"
INFO[0011] retrying command                              attempt=3 backoff=6.35325038s command=0
ERRO[0017] command execution failed                      attempt=3 command=0 error="exit status 1"
Error: command failed after 4 attempts: exit status 1
[Error] command failed after 4 attempts: exit status 1

[gambol99]

LGTM