Update doc when release

[weakish]

现在直接 make doc 会报错 Fatal error: Cannot use 'Object' as class name as it is reserved，还需要切换到 php 5 再跑。

或者干脆去掉 PHP 5 的支持（官方是 2018 年底就 EOL 了）？

[juvenn]

php 的用户往往升级慢，我还是想保留一下 5.5 支持。

make doc 报错，有没有变通的办法可以解决呢？如果实在不行的话，那就抛弃 5.5 吧。

[weakish]

有没有变通的办法可以解决呢

@juvenn 就切到 php5 就行。我提了 suggestion（顺便在跑 make doc 前把 docs 目录删一下，否则 apigen 检测到目录已存在，会提示是否覆盖，还要按一下 enter 确认）

[codecov[bot]]

Codecov Report

Merging #172 into master will not change coverage by %. The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #172   +/-   ##
=========================================
  Coverage     66.89%   66.89%           
  Complexity      802      802           
=========================================
  Files            36       36           
  Lines          2287     2287           
=========================================
  Hits           1530     1530           
  Misses          757      757           

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 8b6af96...9da6de9. Read the comment docs.

[juvenn]

我提了 suggestion

好高级，我 apply suggestion 了。

[juvenn]

但是，我好像不能 approve ，因为是我提的 pr 。你直接 approve merge 吧。