feat: Add test coverage

[wangkailang]

Test coverage

-------------------------|----------|----------|----------|----------|-------------------|
File                     |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
-------------------------|----------|----------|----------|----------|-------------------|
All files                |     5.47 |     7.37 |     5.26 |     5.76 |                   |
 src                     |        0 |        0 |        0 |        0 |                   |
  index.ts               |        0 |        0 |        0 |        0 |                   |
  interface.tsx          |        0 |        0 |        0 |        0 |                   |
 src/components          |        0 |        0 |        0 |        0 |                   |
  index.tsx              |        0 |        0 |        0 |        0 |                   |
 src/components/Badge    |      100 |      100 |      100 |      100 |                   |
  index.tsx              |      100 |      100 |      100 |      100 |                   |
 src/components/Icon     |        0 |      100 |        0 |        0 |                   |
  index.tsx              |        0 |      100 |        0 |        0 |        5,6,7,8,11 |
 src/components/Loader   |        0 |        0 |        0 |        0 |                   |
  index.tsx              |        0 |        0 |        0 |        0 |      8,9,10,11,21 |
 src/components/Tooltip  |        0 |        0 |        0 |        0 |                   |
  index.tsx              |        0 |        0 |        0 |        0 |... 9,51,63,91,123 |
 src/components/UsageBar |        0 |        0 |        0 |        0 |                   |
  index.tsx              |        0 |        0 |        0 |        0 |... 12,115,133,192 |
 src/utils               |        0 |        0 |        0 |        0 |                   |
  bem-class.ts           |        0 |        0 |        0 |        0 |... ,9,10,11,12,14 |
  bulk.ts                |        0 |        0 |        0 |        0 |... 38,40,41,42,44 |
  index.ts               |        0 |        0 |        0 |        0 |                   |
  xbytes.ts              |        0 |        0 |        0 |        0 |... 14,117,118,121 |
-------------------------|----------|----------|----------|----------|-------------------|

Fix

• fix coverage problem: test coverage is empty - v3.0.0 facebook/create-react-app#6888
• yarn add @types/enzyme-adapter-react-16 -D
• Badge coverage 100%