v0.0.7

• Validation decorators are now inherited between classes.
• Fix issue #1: support union types like "number | null":
  • When the "design:type" metadata is "Object", we no longer try to guess the schema type. This means that you need to explicitly decorate the property with a type schema like "ObjectSchema()".
  • "Object" is now an allowed "design:type" for any decorator, no matter what allowed types have been specified in the constraint decorator.
  • The error message given when the Joi schema cannot be inferred from the "design:type" metadata has changed to: No validation schema exists, nor could it be inferred from the design:type metadata, for property "${propertyKey}". Please decorate the property with a type schema.
• Metadata retrieval/storage of the schema is now done at its "own" level, not checking the whole prototype chain.
• @nested() does not allow an implicit design:type of "Object". It also returns a different error message when no nested class has been provided: Could not determine the type of the nested property "${ propertyKey }". Please pass the class to the Nested() decorator.
• Change some "Object" types to "object", since I think they don't actually want to accept "number" or "string" types.
• Update to output ES6 code. (Turns out we're using ES6 functionality anyway, like Object.getPrototypeOf()).
• Keep the working validation schema in a separate bit of metadata. (This will let us implement inheritance, by traversing the prototype chain and combining all schemas.)
• ValidationResult is now a discriminated union, so you can distinguish between validation passes and failure at compile time.
• The @keys() decorator now accepts a type parameter, so you can enforce that the schema you pass in only has keys in the provided type. This should still work without specifying a type parameter.
• Update to TypeScript 2.6
• TypeScript: Turn on all strict options.
• Turn on strict function checks (contravariance checks). This requires changing all constraint decorator update functions, so they accept a "Schema", then casting the schema to the sub-type within the function body.
• Object constraints that relate to peers, such as And, Nand, Xor, OptionalKeys etc, now use "keyof" types and must be passed a type parameter representing the class/type/interface being validated.
• Constraint decorators that accept multiple arguments as a "rest" parameter now enforce that at least one argument must be provided.
• Boolean Truthy and Falsy decorators don't accept a boolean, strangely enough!
• Boolean decorators no longer need to cast the schema to "any", thanks to updated Joi type definitions.
• Remove console.log() statement from verifyPeers()
• package.json: Set engines to allow higher versions.
• package.json: Set "joi" and "@types/joi" as peer dependencies. Allow versions greater than those used for development.
• package.json: Add "joi" as a dev dependency.
• TSC: Don't emit source maps when publishing. Without the .ts files, I don't think they serve any purpose.
• .npmignore is now a whitelist; no more random files getting published to NPM.