make readme badges be on one line

[andrewm4894]

Just a small PR to make the readme badges be on one line.

I was just sharing with a colleague and noticed the badges seem to each be on thier own line in the github readme. Thought could be an easy one for me to try see if can make a little prettier potentially as i love the project.

Can quickly see how it will look here: https://github.com/andrewm4894/pyod/blob/patch-1/README.rst

All Submissions Basics:

• [x] Have you followed the guidelines in our Contributing document?
• [x] Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• [x] Have you checked all Issues to tie the PR to a specific one?

All Submissions Cores:

• [ ] Have you added an explanation of what your changes do and why you'd like us to include them?
• [ ] Have you written new tests for your core changes, as applicable?
• [ ] Have you successfully ran tests with your changes locally?
• [ ] Does your submission pass tests, including CircleCI, Travis CI, and AppVeyor?
• [ ] Does your submission have appropriate code coverage? The cutoff threshold is 95% by Coversall.

New Model Submissions:

• [ ] Have you created a .py in ~/pyod/models/?
• [ ] Have you created a _example.py in ~/examples/?
• [ ] Have you created a test_.py in ~/pyod/test/?
• [ ] Have you lint your code locally prior to submission?

[coveralls]

Pull Request Test Coverage Report for Build 9273495780

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.02%) to 93.73%

---

Totals
Change from base Build 8309424051:	-0.02%
Covered Lines:	8954
Relevant Lines:	9553

---

💛 - Coveralls

[andrewm4894]

Maybe coverage has gone down a little due to deleting a few lines from the readme? Would have thought not, although maybe .rst files can impact this.

[yzhao062]

oh, it is a GitHub issue. no worries. please make the PR to the development branch :)