move the remaining RippleAPI tests to the new test runner

test/api/isConnected/index.ts

@@ -0,0 +1,15 @@
+import assert from 'assert-diff'
+import { TestSuite } from '../../utils'
+
+/**
+ * Every test suite exports their tests in the default object.
+ * - Check out the "TestSuite" type for documentation on the interface.
+ * - Check out "test/api/index.ts" for more information about the test runner.
+ */
+export default <TestSuite>{
+  'disconnect & isConnected': async (api, address) => {
+    assert.strictEqual(api.isConnected(), true)
+    await api.disconnect()
+    assert.strictEqual(api.isConnected(), false)
+  }
+}