title: Use boostrap footer class in navbar shiny layout
body: <p>I want to include footer to my <code>navbarPage</code> shiny layout. There exist footer argument in the main function:
  <a href="https://shiny.rstudio.com/reference/shiny/1.0.5/navbarPage.html" rel="nofollow noreferrer">https://shiny.rstudio.com/reference/shiny/1.0.5/navbarPage.html</a></p>
  
  <p>but I would like to use boostrap classes for footer:
  <a href="https://mdbootstrap.com/docs/jquery/navigation/footer/" rel="nofollow noreferrer">https://mdbootstrap.com/docs/jquery/navigation/footer/</a></p>
  
  <p>So, I would like to know, how to include, for example this HTML code to my shiny App:
  </p>
  
  <pre><code>&lt;footer class="page-footer font-small blue"&gt;
  
    &lt;!-- Copyright --&gt;
    &lt;div class="footer-copyright text-center py-3"&gt;© 2018 Copyright:
      &lt;a href="https://mdbootstrap.com/education/bootstrap/"&gt; MDBootstrap.com&lt;/a&gt;
    &lt;/div&gt;
    &lt;!-- Copyright --&gt;
  
  &lt;/footer&gt;
  &lt;!-- Footer --&gt;
  </code></pre>
  
  <p>I tried:</p>
  
  <pre><code>library(shiny)
  library(shinythemes)
  
  # Define UI for application that draws a histogram
  ui &lt;- fluidPage(
  
    navbarPage("MyApp", 
               theme = shinytheme("flatly"),
               tabPanel("Test"),
               footer = tagList(
                 br(),
                 div(p("test"), class="footer-copyright text-center py-3"),
                 class = "page-footer font-small cyan darken-3"
               )
  
    )
  )
  
  # Define server logic required to draw a histogram
  server &lt;- function(input, output,session) {
  
  }
  
  # Run the application 
  shinyApp(ui = ui, server = server)
  </code></pre>
  
  <p>but it doesn't show nice footer, just plain text.</p>