title: Can't publish R Mardown to Confluence using conflr
body: <p>I'm trying to post r markdown on Confluence using conflr. 
  Once I open the file and click 'Post to Confluence' the knitting process starts and goes all the way to 100% but then I get an error  message (below) and the whole process stops.</p>
  
  <p>followed the steps documented in <a href="https://engineering.linecorp.com/en/blog/conflr-published/" rel="nofollow noreferrer">https://engineering.linecorp.com/en/blog/conflr-published/</a>. I reduced the file to be posted on Confluence to an absolute minimum to try to solve and isolate the error. </p>
  
  <p>I also searched for answers to similar questions here in StackOverflow and on other related resources. However there isn't much documentation available at the moment and could not find an answer. </p>
  
  <p>I tried to post the below text on Confluence form a very simple R markdown file:</p>
  
  <pre><code>---
  title: "conflr test"
  always_allow_html: yes
  ---
  ## Overview
  Test Test Test
  </code></pre>
  
  <p>Was expecting to get a preview of the page after the knitting process but instead got the below error message:</p>
  
  <p><strong>output file</strong>: <code>Conflr_test.knit.md</code></p>
  
  <blockquote>
    <p>C:/Users/MICHAE~1.EMM/AppData/Local/Pandoc/pandoc" +RTS -K512m -RTS
    Conflr_test.utf8.md --to markdown_strict --from
    markdown+autolink_bare_uris+ascii_identifiers-tex_math_single_backslash-tex_math_dollars-raw_tex
    --output Conflr_test.md --standalone --wrap=none</p>
  </blockquote>
  
  <p><strong>Output created:</strong> <code>Conflr_test.md</code></p>
  
  <blockquote>
    <p>Error in conflr:::confl_create_post_from_Rmd() :    promise already
    under evaluation: recursive default argument reference or earlier
    problems?</p>
  </blockquote>