review jobs

[kevindrosendahl]

some things to consider:

• should what is now called jobs be called "job-templates" or something like that?
• how do you deal with supplying commands/args/environments
  • should the template be defaults and fully overwritten?
  • e.g. if i say --env foo=bar does that mean ignore all default env vars or add foo=bar?
  • how to reference secrets

[kevindrosendahl]

closing in favor of https://github.com/mlab-lattice/lattice/issues/208