disallow improve step for big target

disallow improve step for large target amount (#10)

* no improve step for large target amount

* increment version

1.1.0

change factory contract to parametrize transaction size and replace delegation by inheritance for simplicity

New Api with 2 coinselection algorithms

• differentiate between random-improve and largest-first method
• enclose non-public methods
• add test for largest-first method
• bump version

v0.0.7

add op return output functionality

v0.0.6

add filter to not include inputs that are smaller than fee

v0.0.5

Fix fee calculation for the compulsory list

v0.0.4

Undergo large refactoring and add compulsory utxos - might you want to include them. Very handy if you are dealing with Omni transactions.

v0.0.3

Fix bugs and update tests

v0.0.2

Added check for total utxo amount
Returns optional utxo list

Initial release

0.0.1

init commit