fix for AQCU-735

[mhines-usgs]

applyDates was null sometimes and causing problems, so if applyDates was null, I turned them into NAs so it would properly shape into a df

[coveralls]

Coverage increased (+0.09%) to 71.707% when pulling 6797dfc on mhines-usgs:master into 64b4eb3 on USGS-R:master.

[lindsayplatt]

You shouldn't need to have the for loop. Just making dataIn$applyDates <- NA will work because data.frame will automatically fill in the other NAs. @mhines-usgs I'll go ahead and make a fix for this since you are traveling!

Example:

dataIn <- list(values = 1:10, dates = 1:10, applyDates = NULL)
as.data.frame(dataIn)

Error in data.frame(values = 1:10, dates = 1:10, applyDates = NULL, check.names = TRUE,  : 
  arguments imply differing number of rows: 10, 0

dataIn <- list(values = 1:10, dates = 1:10, applyDates = NA)
as.data.frame(dataIn)
   values dates applyDates
1       1     1         NA
2       2     2         NA
3       3     3         NA
4       4     4         NA
5       5     5         NA
6       6     6         NA
7       7     7         NA
8       8     8         NA
9       9     9         NA
10     10    10         NA