The Fibonacci Sequence
======================

The fibonacci sequence are the numbers in the following integer sequence:  
```
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, ...and so on
```
Write a function that detects whether its input is a fibonacci number or not.

Make sure the assert statements all pass. Write two of your own Python assert statements.

## Resources

[Fibonacci Numbers](http://en.wikipedia.org/wiki/Fibonacci_number)  
[Fibonacci in Nature](http://jwilson.coe.uga.edu/emat6680/parveen/fib_nature.htm)  
