Add support for v8-canary, nightly and rc (#655)

src/distributions/rc/rc_builds.ts

@@ -0,0 +1,12 @@
+import BaseDistribution from '../base-distribution';
+import {NodeInputs} from '../base-models';
+
+export default class RcBuild extends BaseDistribution {
+  constructor(nodeInfo: NodeInputs) {
+    super(nodeInfo);
+  }
+
+  getDistributionUrl(): string {
+    return 'https://nodejs.org/download/rc';
+  }
+}