Removed unused variables
Changed In the Item class, the property  is declared to be of type float. Added more tests for setPrice
die changed to throw exceptions
Update ItemTest.php
Merge pull request #83 from bitpay/minorbugfixes

Minorbugfixes
Fix for expected private key length

We're working with the decimal form of the number here, so it can be slightly variable since any leading zeroes from the hex are not used.  I generated 1,000,000 keys and the range of sizes were:

Array
(
    [0] => 78
    [1] => 77
    [2] => 76
    [3] => 75
    [4] => 74
    [5] => 73
    [6] => 72
)

I think it's safe to say we shouldn't see anything less than 72, although it's still theoretically possible since the number can be in the range of [1, n-1].