Merge pull request bitcoin-education#15 from bitcoin-education/4.1

update dependencies

Merge pull request bitcoin-education#8 from bitcoin-education/script-…

…to-address

adding script to address methods

Merge pull request bitcoin-education#7 from bitcoin-education/script-…

…identification

adding script identification methods

Merge pull request bitcoin-education#6 from bitcoin-education/add-ove…

…rloaded-method

add overloaded method to extended pubkey

Merge pull request bitcoin-education#5 from bitcoin-education/adding-…

…prefix

adding prefix as parameter to extended key methods

Merge pull request bitcoin-education#4 from bitcoin-education/unseria…

…lize

adding extended keys unserialization