arcgis-rest-js packages should be peer dependencies of cedar

[tomwayson]

cedar/packages/cedar/package.json

Lines 66 to 68 in db41632

	"@esri/arcgis-rest-common-types": "^1.7.1",
	"@esri/arcgis-rest-feature-service": "^1.7.1",
	"@esri/arcgis-rest-request": "^1.7.1",

should be moved to peerDependencies.

[tomwayson]

Also, will need to update the "will be installed for you" wording here: https://github.com/Esri/cedar#dependencies

[tomwayson]

hm... on second thought, not sure about this now, based on this rule, it's not like cedar's a plugin of rest-js.