This PR adds a new Storage Backend for Triton's Object Storage - Manta
```
make testacc TEST=./physical/manta
==> Checking that code complies with gofmt requirements...
==> Checking that build is using go version >= 1.9.1...
go generate
VAULT_ACC=1 go test -tags='vault' ./physical/manta -v -timeout 45m
=== RUN TestMantaBackend
--- PASS: TestMantaBackend (61.18s)
PASS
ok github.com/hashicorp/vault/physical/manta 61.210s
```
Manta behaves differently to how S3 works - it has no such concepts of Buckets - it is merely a filesystem style object store
Therefore, we have chosen the approach of when writing a secret `foo` it will actually map (on disk) as foo/.vault_value
The reason for this is because if we write the secret `foo/bar` and then try and Delete a key using the name `foo` then Manta
will complain that the folder is not empty because `foo/bar` exists. Therefore, `foo/bar` is written as `foo/bar/.vault_value`
The value of the key is *always* written to a directory tree of the name and put in a `.vault_value` file.
* Use Colored UI if stdout is a tty
* Add format options to operator unseal
* Add format test on operator unseal
* Add -no-color output flag, and use BasicUi if no-color flag is provided
* Move seal status formatting logic to OutputSealStatus
* Apply no-color to warnings from DeprecatedCommands as well
* Add OutputWithFormat to support arbitrary data, add format option to auth list
* Add ability to output arbitrary list data on TableFormatter
* Clear up switch logic on format
* Add format option for list-related commands
* Add format option to rest of commands that returns a client API response
* Remove initOutputYAML and initOutputJSON, and use OutputWithFormat instead
* Remove outputAsYAML and outputAsJSON, and use OutputWithFormat instead
* Remove -no-color flag, use env var exclusively to toggle colored output
* Fix compile
* Remove -no-color flag in main.go
* Add missing FlagSetOutputFormat
* Fix generate-root/decode test
* Migrate init functions to main.go
* Add no-color flag back as hidden
* Handle non-supported data types for TableFormatter.OutputList
* Pull formatting much further up to remove the need to use c.flagFormat (#3950)
* Pull formatting much further up to remove the need to use c.flagFormat
Also remove OutputWithFormat as the logic can cause issues.
* Use const for env var
* Minor updates
* Remove unnecessary check
* Fix SSH output and some tests
* Fix tests
* Make race detector not run on generate root since it kills Travis these days
* Update docs
* Update docs
* Address review feedback
* Handle --format as well as -format
