Add the EnvUser with tests. Create an Environment user during bootstrap

Added the EnvUser doc

Support for setting the last login time for the EnvUser

Added a factory for adding the envuser

Admin EnvUser gets added at bootstrap time

Removed a couple of attributes from the upgrade package that no longer needed to be there

What does 
```
var t time.Time
```
marshal into json/yaml as ? `time.Time` has a `isZero` method so you don't need to use a pointer to signify 'invalid time'