This commit refactors the query package tests to use the
standard library testing package instead of goconvey. Goconvey
is now completely removed from the repository.
This commit updates the import path from:
```
pilosa/*
```
to:
```
github.com/umbel/pilosa/*
```
This follows standard Go convention and makes the project "go gettable".
The README was also updated to reflect the changes.
