use cached data to speed up building of vignettes

vignettes/osem-history.Rmd

@@ -43,7 +43,7 @@ So the first step is to retrieve *all the boxes*:
 ```{r download}
 # if you want to see results for a specific subset of boxes,
 # just specify a filter such as grouptag='ifgi' here
-boxes = osem_boxes()
+boxes = osem_boxes(cache = '.')
 ```
 
 # Plot count of boxes by time {.tabset}

vignettes/osem-history_revised.Rmd

@@ -45,7 +45,7 @@ So the first step is to retrieve *all the boxes*.
 ```{r download, results='hide', message=FALSE, warning=FALSE}
 # if you want to see results for a specific subset of boxes,
 # just specify a filter such as grouptag='ifgi' here
-boxes_all = osem_boxes()
+boxes_all = osem_boxes(cache = '.')
 boxes = boxes_all
 ```
 # Introduction

vignettes/osem-intro.Rmd

@@ -32,7 +32,7 @@ datasets' structure.
 library(magrittr)
 library(opensensmapr)
 
-all_sensors = osem_boxes()
+all_sensors = osem_boxes(cache = '.')
 ```
 ```{r}
 summary(all_sensors)
@@ -101,7 +101,7 @@ We could call `osem_measurements(pm25_sensors)` now, however we are focusing on
 a restricted area of interest, the city of Berlin.
 Luckily we can get the measurements filtered by a bounding box:
 
-```{r}
+```{r. eval = FALSE}
 library(sf)
 library(units)
 library(lubridate)