re-debug styx-simulation pipeline

[aappling-usgs]

stage_calc_ts, stage_styx_site, post_styx_site, config_to_metab_repeat used for SB model experiment 0.0.19

[aappling-usgs]

appveyor can't find devtools. travis is failing on the same suite of real errors as other recent PRs.

testthat results ================================================================
OK: 60 SKIPPED: 0 FAILED: 8
1. Error: combine_ts works 
2. Error: config files can be staged 
3. Error: config files can be verified 
4. Error: get_ts works 
5. Failure (at test-list_and_get_info.R#5): internal function get_sites works for multisites 
6. Failure (at test-list_and_get_info.R#6): internal function get_sites works for multisites 
7. Error: list_datasets  
8. Error: get_site_coords works 

Error: testthat unit tests failed
In addition: Warning messages:
1: In is.na(x) : is.na() applied to non-(list or vector) of type 'NULL'
2: In is.na(x) : is.na() applied to non-(list or vector) of type 'NULL'

for comparison, build request #236 had 35 more OKs and 2 fewer failures:

testthat results ================================================================
OK: 95 SKIPPED: 0 FAILED: 6
1. Error: config files can be verified 
2. Error: get_ts works 
3. Failure (at test-list_and_get_info.R#5): internal function get_sites works for multisites 
4. Failure (at test-list_and_get_info.R#6): internal function get_sites works for multisites 
5. Error: list_datasets  
6. Error: get_site_coords works 

Error: testthat unit tests failed
In addition: Warning messages:
1: In is.na(x) : is.na() applied to non-(list or vector) of type 'NULL'
2: In is.na(x) : is.na() applied to non-(list or vector) of type 'NULL'
Execution halted