feat(module:inputNumber): limit integer, decimal input and decimal in…

[giscafer]

…put control by nzStep

nzStep is a integer,limit only integer input

close #42

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/NG-ZORRO/ng-zorro-antd/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Application (the showcase website) / infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

[x] Yes
[ ] No

Other information

[coveralls]

Coverage remained the same at 52.163% when pulling e8f8f9e on giscafer:inputNumber-limit-input into 44865c2 on NG-ZORRO:master.

[vthinkxie]

thanks for your pr very much.
I suggest this component should keep the same behavior as https://ant.design/components/input-number-cn/ that user can input any char but the value will be validated when blur event is triggered.

[vthinkxie]

I'll close the PR for the time being.
Please comment if I'm missing something.