message: update blockstack-keychains to 0.0.8. fixes
diff: {
  "name": "blockstack",
  - "version": "0.2.9",
  + "version": "0.2.10",
  "description": "The Blockstack Javascript library for identity and authentication.",
  "main": "lib/index",
  "scripts": {
  "base64url": "^2.0.0",
  "bigi": "^1.4.1",
  "bitcoinjs-lib": "^2.3.0",
  - "blockstack-keychains": "0.0.4",
  + "blockstack-keychains": "0.0.8",
  "dateformat": "^1.0.12",
  "ecurve": "^1.0.5",
  "elliptic": "^6.4.0",
  