v1.0.2

• Callable modules, issue #213.
• Install modules using a GitHub repository and module.json, pr #216.
• Added refresh_module() function, issue #217.
• Added log function, pr #218.
• Fixed bug with nested futures, issue #219.
• Added basic JSON support, issue #220.
  • json_dump(): https://docs.thingsdb.net/v1/collection-api/json_dump/
  • json_load(): https://docs.thingsdb.net/v1/collection-api/json_load/
• Accept zero arguments for the wrap() function, issue #223.