a) Write a function called cel2fahr for converting Celsius
temperatures to their Fahrenheit equivalent.

b) Write a program that uses cel2fahr to generate a table of Celsius
temperatures and their Fahrenheit equivalent.  The output of your
program should look like this, including the header and dashed line
(but ?? is replaced by the right value):

  Temperature chart 
Celsius    Fahrenheit
---------------------
  0         ??
 10         ??
 20         ??
 30         ??
 40         ??
 50         ??