Type checking false positive for dynamic object properties

[tsandall]

The ref checker returns false positives for dynamic object property keys that are not strings. The type system needs to be updated so that dynamic object properties have key types in addition to value types.

> show
package repl

p[q] = 1

q = 1

version = {
	"Version": "0.5.7-dev",
	"BuildCommit": "e0586342-dirty",
	"BuildTimestamp": "2017-08-31T00:17:38Z",
	"BuildHostname": "spacebox.local",
}

> p[1]
1
> x = 1; p[x]
1 error occurred: 1:8: rego_type_error: undefined ref: data.repl.p[x]
	data.repl.p[x]
	            ^
	            have (type): number
	            want (type): string