* update modules * fix import problem regarding collections
1.6
* support method-chain style coding to create transaction object
1.5.6
* modify dynamic link library load procedure for AWS lambda
1.5.5
* bug fix on reading PEM key file
1.5.4
* bug fix
1.5.3
* implement python cryptography module based KeyPair class (KeyPairPy) * py-bbclib module works without libbbcsig library (fallback mode) - building libbbcsig becomes optional, so pip installation speed becomes quite faster.