feat(supported-versions): add release date (#100)

Previously, we didn't take into account a release date, which meant
that @vinai could not add MageOS or Magento releases before the actual
day of release.

With this, we can now add the releases to supported verisons before
a release comes out, allowing us to make a kind that allows testing
MageOS and Magento Mirror releases more quickly.

supported-version/src/matrix/matrix-type.ts

@@ -9,6 +9,7 @@ export interface MagentoMatrixVersion {
     varnish: string,
     nginx: string,
     os: string,
+    release: string,
     eol: string
 }