fix(unit): don't panic on bad lines in unit files
fix(unit): propagate NewUnit errors
chore(agent): centralize NewJob/NewUnit invocations in agent test
chore(fleetctl): centralize NewJob/NewUnit invocation in fleetctl tests
chore(agent): centralize NewJob/NewUnit invocations in agent state test
chore(job): centralize NewUnit invocations in job_test
chore(registry): handle NewUnit errors in registry tests
chore(sign): handle NewUnit errors in signing tests
fix(fleetctl): sort metadata explicitly by keys
Merge pull request #551 from jonboulle/testfix

fix(fleetctl): sort metadata explicitly by keys
Merge pull request #546 from jonboulle/546

fix(unit): fix panic on malformed unit files, and clean up tests
feat(API): Add GET /units to schema
feat(API): Implement GET /units
fix(API): s/Error/Errorf/
refactor(API): s/extractPage/extractMachinePage/
refactor(API): simplify list-mapping routine
refactor(API): simplify machine list-mapping
refactor(API): surface error from mapUnitToJob
refactor(API): encapsulate unit states
fix(API): fill out MachineState objects