feat(supported-version): add user-defined kind (#28)

`kind` is a new input property for the `supported-version` action which
allows one to define what specific versions of Magento they support.

Currently, `kind` supports `latest`, `currently-supported`, and `custom`. See the
README for `supported-version` if you want more specifics

supported-version/jest.config.js

@@ -0,0 +1,9 @@
+module.exports = {
+    clearMocks: true,
+    moduleFileExtensions: ['js', 'ts'],
+    testMatch: ['**/*.spec.ts'],
+    transform: {
+        '^.+\\.ts$': 'ts-jest'
+    },
+    verbose: true
+}