Rename RippleAPI client to Client (#1520)

* rename RippleAPI -> XrplClient

* more renames

* move API stuff to client folder

* rename all api -> client

* fix tests

* make tests run

* fix integ tests

* fix urls

* fix merge issues

* XrplClient -> Client

* fix merge issues

* rename xrpl-client npm symlink to xrpl-local

test/client/getFeeBase/index.ts

@@ -0,0 +1,14 @@
+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/client/index.ts" for more information about the test runner.
+ */
+export default <TestSuite>{
+  'default test': async (client, address) => {
+    const fee = await client.connection.getFeeBase()
+    assert.strictEqual(fee, 10)
+  }
+}