Ignore stan block when adding names

[ignacio82]

Describe the bug

The chunkname function breaks stan code chunks.

To Reproduce

Create the following markdown:

---
title: "test"
output: html_document
---

` ``{r}

` ``


` ``{stan output.var="test"}

` ``

Use the adding for naming the code chunks:

---
title: "test"
output: html_document
---

` ``{r remedy01}

` ``


` ``{r remedy02,="test"}

` ``

Expected behavior

---
title: "test"
output: html_document
---

` ``{r remedy01}

` ``

` ``{stan output.var="test"}

` ``

Environment (please complete the following information):

Session Info

> devtools::session_info()
- Session info ---------------------------------------------------------------------------------------------
setting  value                       
version  R version 3.5.1 (2018-07-02)
os       Windows >= 8 x64            
system   x86_64, mingw32             
ui       RStudio                     
language (EN)                        
collate  English_United States.1252  
ctype    English_United States.1252  
tz       America/New_York            
date     2019-04-01                  

- Packages -------------------------------------------------------------------------------------------------
package     * version date       lib source        
assertthat    0.2.0   2017-04-11 [1] CRAN (R 3.5.1)
backports     1.1.3   2018-12-14 [1] CRAN (R 3.5.2)
callr         3.2.0   2019-03-15 [1] CRAN (R 3.5.3)
cli           1.0.1   2018-09-25 [1] CRAN (R 3.5.1)
colorspace    1.4-0   2019-01-13 [1] CRAN (R 3.5.2)
crayon        1.3.4   2017-09-16 [1] CRAN (R 3.5.1)
desc          1.2.0   2018-05-01 [1] CRAN (R 3.5.1)
devtools      2.0.1   2018-10-26 [1] CRAN (R 3.5.2)
digest        0.6.18  2018-10-10 [1] CRAN (R 3.5.1)
dplyr         0.8.0.1 2019-02-15 [1] CRAN (R 3.5.2)
fs            1.2.6   2018-08-23 [1] CRAN (R 3.5.1)
ggplot2       3.1.0   2018-10-25 [1] CRAN (R 3.5.1)
glue          1.3.1   2019-03-12 [1] CRAN (R 3.5.3)
gridExtra     2.3     2017-09-09 [1] CRAN (R 3.5.1)
gtable        0.2.0   2016-02-26 [1] CRAN (R 3.5.1)
hms           0.4.2   2018-03-10 [1] CRAN (R 3.5.1)
inline        0.3.15  2018-05-18 [1] CRAN (R 3.5.1)
knitr         1.22    2019-03-08 [1] CRAN (R 3.5.3)
lazyeval      0.2.1   2017-10-29 [1] CRAN (R 3.5.1)
loo           2.0.0   2018-04-11 [1] CRAN (R 3.5.1)
magrittr      1.5     2014-11-22 [1] CRAN (R 3.5.1)
matrixStats   0.54.0  2018-07-23 [1] CRAN (R 3.5.1)
memoise       1.1.0   2017-04-21 [1] CRAN (R 3.5.2)
munsell       0.5.0   2018-06-12 [1] CRAN (R 3.5.1)
pillar        1.3.1   2018-12-15 [1] CRAN (R 3.5.2)
pkgbuild      1.0.2   2018-10-16 [1] CRAN (R 3.5.1)
pkgconfig     2.0.2   2018-08-16 [1] CRAN (R 3.5.1)
pkgload       1.0.2   2018-10-29 [1] CRAN (R 3.5.2)
plyr          1.8.4   2016-06-08 [1] CRAN (R 3.5.1)
prettyunits   1.0.2   2015-07-13 [1] CRAN (R 3.5.1)
processx      3.3.0   2019-03-10 [1] CRAN (R 3.5.3)
ps            1.3.0   2018-12-21 [1] CRAN (R 3.5.2)
purrr         0.3.0   2019-01-27 [1] CRAN (R 3.5.2)
R6            2.4.0   2019-02-14 [1] CRAN (R 3.5.2)
Rcpp          1.0.1   2019-03-17 [1] CRAN (R 3.5.3)
readr         1.3.1   2018-12-21 [1] CRAN (R 3.5.2)
rematch2      2.0.1   2017-06-20 [1] CRAN (R 3.5.3)
remedy        0.1.0   2018-12-03 [1] CRAN (R 3.5.3)
remotes       2.0.2   2018-10-30 [1] CRAN (R 3.5.2)
rlang         0.3.2   2019-03-21 [1] CRAN (R 3.5.3)
rprojroot     1.3-2   2018-01-03 [1] CRAN (R 3.5.2)
rstan         2.18.2  2018-11-07 [1] CRAN (R 3.5.1)
rstudioapi    0.9.0   2019-01-09 [1] CRAN (R 3.5.2)
scales        1.0.0   2018-08-09 [1] CRAN (R 3.5.1)
sessioninfo   1.1.1   2018-11-05 [1] CRAN (R 3.5.2)
StanHeaders   2.18.1  2019-01-28 [1] CRAN (R 3.5.2)
tibble        2.0.1   2019-01-12 [1] CRAN (R 3.5.2)
tidyselect    0.2.5   2018-10-11 [1] CRAN (R 3.5.1)
usethis       1.4.0   2018-08-14 [1] CRAN (R 3.5.2)
withr         2.1.2   2018-03-15 [1] CRAN (R 3.5.1)
xfun          0.5     2019-02-20 [1] CRAN (R 3.5.3)
yaml          2.2.0   2018-07-25 [1] CRAN (R 3.5.1)

[1] C:/Users/imartinez/Documents/R/win-library/3.5
[2] C:/Program Files/R/R-3.5.1/library