title: dplyr::select - programatically rearrange columns using character variable for column name
body: <p>I want to re-arrange the columns of a df using <code>dplyr::select</code> programatically<br>
  A non R user is going to execute the code and this person will provide two inputs as follows: <br></p>
  
  <pre><code>report.month &lt;- "Jul"
  report.year  &lt;- 2017
  </code></pre>
  
  <p>Only the month will change, all other names in the df will be the same</p>
  
  <h1>df that I want to re-arrange looks as follows: <br></h1>
  
  <pre><code>df1 &lt;- data.frame(
       country = "AU",
      Jul_2017 = 500,
      Customer = "some guy")
  </code></pre>
  
  <h1>This is the output that I want <br></h1>
  
  <pre><code>  country Customer Jul_2017
         AU some guy      500
  </code></pre>
  
  <h1>This is what I tried, which does not work and I have run out of ideas: <br></h1>
  
  <pre><code>    reporting.month.name &lt;- as.symbol(paste(report.month, report.year, sep = "_"))
  
      df1 %&gt;% select(country, Customer, reporting.month.name)
  Error: `reporting.month.name` must resolve to integer column positions, not a symbol
  </code></pre>
  
  <p>Any advice/help is very much appreciated</p>