lab_find.h

/* Write a function to find the position of the first occurance
  of a given value in a vector.
  
  The function must be called find_position.
  It must take 3 parameters:
    - an iterator to the beginning of a vector of integers
    - an iterator to the end of a vector of integers
    - an integer value to search for

  The function must return an integer representing the position of 
  the search value in the vector.
  If the value is not in the vector then you should return -1
*/