Merge branch 'release/v0.1.1' into develop

* release/v0.1.1:
  bumps version
Fix typo
Record VCR for spec
Expose address_str in Transaction
Fix spec; upgrade bitcoin_testnet
Fixes spec
Fixes listing all recent transactions of wallet
Forgot to include vcr cassette
Prepare v0.2.0
Merge branch 'release/v0.2.0'