Add .info to upload payload (#141)

* Add .info to upload payload
everywhere else as well

+ Upload payload includes Info
+ CLI uploads `version.info` as blob to storage
+ Getter and Saver methods updated for all storages implemented
+ Migration updated to include Info column
+ Tests no longer check RevInfo, now checking for Info same as Zip
+ Updated docs

* newline in .fizz

* change RevInfo.Info to []byte

+ change to []byte instead of io.Reader
+ adjust tests to check for info byte contents directly
+ add error check for minio client GetObject `pkg/storage/minio/getter.go`

pkg/storage/mongo/saver.go

@@ -3,12 +3,13 @@ package mongo
 import "github.com/gomods/athens/pkg/storage"
 
 // Save stores a module in mongo storage.
-func (s *ModuleStore) Save(module, version string, mod, zip []byte) error {
+func (s *ModuleStore) Save(module, version string, mod, zip, info []byte) error {
 	m := &storage.Module{
 		Module:  module,
 		Version: version,
 		Mod:     mod,
 		Zip:     zip,
+		Info:    info,
 	}
 
 	c := s.s.DB(s.d).C(s.c)