Create release v1.2.0

[WadeBarnes]

Create an official v1.2.0 release.

Review and update release docs as needed.

Dependencies:

• https://github.com/hyperledger/indy-node/issues/1828
• https://github.com/hyperledger/indy-plenum/issues/1645
• https://github.com/sovrin-foundation/token-plugin/pull/459

[WadeBarnes]

Several updates were required to complete the release:

Sovrin

• https://github.com/sovrin-foundation/sovrin/pull/360
• https://github.com/sovrin-foundation/sovrin/pull/359
• https://github.com/sovrin-foundation/sovrin/pull/357
• https://github.com/sovrin-foundation/sovrin/pull/356
• https://github.com/sovrin-foundation/sovrin/pull/355
• https://github.com/sovrin-foundation/sovrin/pull/354

Token Plugins

• https://github.com/sovrin-foundation/token-plugin/pull/459
• https://github.com/sovrin-foundation/token-plugin/pull/458
• https://github.com/sovrin-foundation/token-plugin/pull/457
• https://github.com/sovrin-foundation/token-plugin/pull/456
• https://github.com/sovrin-foundation/token-plugin/pull/455
• https://github.com/sovrin-foundation/token-plugin/pull/454
• https://github.com/sovrin-foundation/token-plugin/pull/453
• https://github.com/sovrin-foundation/token-plugin/pull/452

Indy-test-automation

• https://github.com/hyperledger/indy-test-automation/pull/138
• https://github.com/hyperledger/indy-test-automation/pull/136

[WadeBarnes]

Release v1.2.0 complete.