Port the plugins to not use EnvName.
Make sure the make targets check the dependencies.
Only do godeps when environment set.
Merge pull request #247 from howbazaar/make-godep

Make sure the make targets check the dependencies.

I tend to run the tests with 

```
make check
```

and I get annoyed when things are out of date.  This branch adds additional make targets to run the godeps command when building, checking or installing.
Merge pull request #260 from howbazaar/env-cmd-plugins

Port the plugins to not use EnvName.

This branch introduces another intermediate structure that provides a method to prepare the environment.
Don't pass pointers to set.Strings reference values

set.Strings is already a map type, a reference value if you like, so there is no need to pass its address, you're already passing a pointer to it.
Merge pull request #262 from davecheney/129-set-strings-is-already-a-reference-type

Don't pass pointers to set.Strings reference values

set.Strings is already a map type, a reference value if you like, so there is no need to take its address, you're already passing a pointer to it.
Push the key manager into the environment command.
Only expose the root in the base env command.
Update imports.
Implement the client api in terms of the root.