In my system (MBPr 13), printing the current version takes over 2
seconds:
```sh
$ time ./bin/resin version
2.4.0
./bin/resin version 1.37s user 0.19s system 73% cpu 2.130 total
```
The CLI takes almost all of these time to parse the dependency tree
before returning control over the actually called command.
To mitigate this problem, we only require the NPM dependencies a command
requires when executing such command, and thus prevent dependencies from
being required and parsed unnecessary.
After this improvement, printing the original example (`resin version`)
returns in less than a second (2x improvement):
```sh
$ time ./bin/resin version
2.4.0
./bin/resin version 0.88s user 0.09s system 102% cpu 0.938 total
```
This is useful in the scenario when the user is using the CLI in an
environment in which he/she doesn't have access to a web browser, like a
headless server or a Vagrant development environment.
When you change the `resinUrl` config from time to time it can be
confusing to remember where you're logging in, or in which host you're
in.
Currently I have to check the configuration files/environment variables
manually or run `resin settings`.
This PR prints the detected resin url on `resin login` and `resin
whoami` so it's always clear where you are.
This enforces all clients to use the Resin Settings Client version that
the SDK provides, reducing incompatibilities caused by different modules
requiring different Resin Settings Client versions.
Consider the following case:
The SDK is configured to point to staging, but the user passes a token
from production, or viceversa. Since the token is valid in a sense that
is valid JWT and contains real data, the CLI will report as a success.
The user will then get Unauthorized errors when using the API.
