title: Julia convert number to string in scientific notation
body: <p>Does Julia have a way to convert a number to scientific notation in the string type? </p>
  
  <p>For instance: </p>
  
  <p>300 becomes "3.00E+02"
      or 
  0.0045 becomes "4.5E-03"
      or 
  3.14159 becomes "3.14159E+00"</p>