Minor changes

Tried to unify style a little bit.

In particular, I've removed instances of `write-host`. Unless there was a conscious reason to use it, it should always be avoided.

http://www.jsnover.com/blog/2013/12/07/write-host-considered-harmful/
Either that or maybe this:

```
$vp = $VerbosePreference; $VerbosePreference = "continue"; .\foo.ps1; $VerbosePreference = $vp
```

here:

https://github.com/randy3k/UnitTesting/blob/master/appveyor.yml#L18

But as long as we're not using `write-host`, we should be good.

BTW, Appveyor understands script blocks (not the PS concept, Appveyor's), so it should be easier to turn on the verbose stream.