Add use case examples / unexpected error

[cboettig]

This whole package looks pretty amazing.

It seems like it wouldn't be too difficult to replicate some figures from the literature in order to illustrate this package use. For instance, I thought this one might make a splashy example:

http://www.nature.com/nature/journal/v394/n6696/abs/394839b0.html

After looking up the species id for the red lilac successfully, I tried:

out <- getallobssp(speciesid = 35, startdate="1960-01-01", enddate="1994-01-01")

and got this error

Error in data.frame(phenophase_id = "76", phenophase_name = "First leaf",  : 
  arguments imply differing number of rows: 1, 0

(Provided this works, it would be fun to update the original figure with data since 1994 as well...)

Some of Lizzie's papers might be nice potential examples too: https://www.usanpn.org/biblio?f[author]=4604

[sckott]

Hey @cboettig Nice, good idea on the use case for sure. Let's do that when this error is fixed. I'll open another issue for this error.

To be honest, I haven't worked on this in a while - I think I was waiting on some API changes or something. I'll check back in with the developer.

[npnlee85]

Package has this error fixed, and includes vignettes with a number of examples not unlike the graph provided in the linked paper. Also it's now possible to use the package to pull the Spring Index values directly!