add a blank block

+/yarn.lock
+/package-lock.json
+/dist
+/node_modules
+/pages
+.umi
+.umi-production

+export default {
+  plugins: [
+    ['umi-plugin-block-dev', {
+      'layout': 'ant-design-pro',
+    }],
+    ['umi-plugin-react', {
+      'dva': true,
+      'antd': true,
+    }]
+  ],
+}

+The MIT License (MIT)
+
+Copyright (c) 2018-present yutingzhao1991 (yutingzhao1991@sina.com)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

+# @umi-material/blank
+
+A blank block for quick start a umi page develop.
+
+## Usage
+
+```sh
+umi block https://github.com/umijs/umi-blocks/tree/master/blank
+```
+
+## LICENSE
+
+MIT

+{
+  "name": "@umi-block/blank",
+  "version": "0.0.1",
+  "description": "A blank block for quick start a umi page develop.",
+  "main": "src/index.js",
+  "scripts": {
+    "dev": "umi dev"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/umijs/umi-blocks/blank"
+  },
+  "dependencies": {
+    "react": ">=16.0.0",
+    "umi-request": "^1.0.0"
+  },
+  "devDependencies": {
+    "umi": "^2.3.0-beta.1",
+    "umi-plugin-block-dev": "^1.0.0",
+    "umi-plugin-react": "^1.3.0-beta.1"
+  },
+  "authors": [
+    "yutingzhao1991 <yutingzhao1991@sina.com>"
+  ],
+  "license": "ISC"
+}

+export default {
+  'GET /api/text': {
+    text: 'I am a blank block',
+  },
+};

+import React, { Component } from 'react';
+import { Button } from 'antd';
+import { connect } from 'dva';
+
+import styles from './style.less';
+
+// TODO: Page 修改为有意义的名称
+@connect(({ page }) => page)
+class Page extends Component {
+  componentDidMount() {
+    const { dispatch } = this.props;
+    dispatch({
+      type: 'page/fetch',
+    });
+  }
+
+  render() {
+    const { text } = this.props;
+    return (
+      <div className={styles.container}>
+        <Button>{text}</Button>
+      </div>
+    );
+  }
+}
+
+export default Page;

+import { getText } from './service';
+
+export default {
+  namespace: 'page', // TODO: 修改为有意义的 namespace
+  state: {
+    text: 'loading...',
+  },
+
+  effects: {
+    *fetch(_, { call, put }) {
+      const { text } = yield call(getText);
+      yield put({
+        type: 'save',
+        payload: {
+          text,
+        },
+      });
+    },
+  },
+
+  reducers: {
+    save(state, { payload }) {
+      return {
+        ...state,
+        ...payload,
+      };
+    },
+  },
+};

+import request from 'umi-request';
+
+export function getText() {
+  return request('/api/text');
+}

+.container {
+  padding: 8px;
+}