fix go version on deploy

postgres.Load isn't mandatory for all commands (prest#319)

* postgres.Load ins't mandatory for all commands

migrate and version commands can be ran without driver load

* update prest/cmd pkg

* closes prest#318

use vendor path on ldflags (prest#314)

Ref: prest#313

first release using @goreleaser

fix repo url on doc.go

Remove duplicated section about debug mode

set new release 0.1.7

set new release 0.1.6

set new release 0.1.5

Added version command line (prest#125)

* added version command line
print current version pREST

* create migrate version cmd