Fix multiple bugs

[Hexcles]

See the three commits for detail.

[landscape-bot]

Repository health increased by 2% when pulling 1557090 on Hexcles:master into dfb6c78 on taizilongxu:master.

• No new problems were introduced.
• 2 problems were fixed (including 0 errors and 2 code smells).

[Hexcles]

噗……我们好像没有写测试和build，用不了CI……

[landscape-bot]

Repository health increased by 3% when pulling 1d98f4f on Hexcles:master into dfb6c78 on taizilongxu:master.

• No new problems were introduced.
• 3 problems were fixed (including 0 errors and 3 code smells).

[landscape-bot]

Repository health increased by 4% when pulling 33035b3 on Hexcles:master into dfb6c78 on taizilongxu:master.

• No new problems were introduced.
• 4 problems were fixed (including 0 errors and 4 code smells).

[taizilongxu]

这个不是ci啊，最近发现的，可以帮助改进代码质量

[Hexcles]

你说的是 landscape 。然后你把 travis 也开起来了， travis 是 CI 。

应该是可以单独用 landscape 不用 travis 的吧？

[landscape-bot]

Repository health increased by 4% when pulling 39b88ab on Hexcles:master into dfb6c78 on taizilongxu:master.

• 2 new problems were found (including 0 errors and 2 code smells).
• 6 problems were fixed (including 0 errors and 6 code smells).

[landscape-bot]

Repository health increased by 4% when pulling cf09589 on Hexcles:master into dfb6c78 on taizilongxu:master.

• 1 new problem was found (including 0 errors and 1 code smell).
• 6 problems were fixed (including 0 errors and 6 code smells).

[taizilongxu]

@Hexcles 对的,我记的把ci关了的,你怎么知道我开的ci啊?

[Hexcles]

你看这个PR页面的底下总是有一个 travis CI 的 build failed 的提示

[taizilongxu]

好的 我去关一下~~ಠ౪ಠ