Difficulty building the vignette

When I attempt to build the vignette, I get the following error:

> Error in predictSolute.loadComp(no3_lc, "flux", estdat, se.pred = TRUE) :
Uncertainty estimates were not stored with the model. Refit with 'uncertainty' in 'store' argument to enable se.pred=TRUE

I'm able to fix the error by storing the uncertainty when creating `no3_lc`:

```r
no3_lc <- loadComp(reg.model=no3_lr, interp.format="conc",
interp.data=intdat, store = "uncertainty")
```

Would a PR that allows the vignette to be built be welcome?