[DOC] Removes LGTM Badges from README.md

[ooprathamm]

• Closes #xxxx
• I am familiar with the contributing guidelines
• Tests added
• Updates entries in docs/sphinx/source/reference for API changes.
• Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.
• Pull request is nearly complete and ready for detailed review.
• Maintainer: Appropriate GitHub Labels (including remote-data) and Milestone are assigned to the Pull Request and linked Issue.

[ooprathamm]

@mikofski this PR removes code quality row (containing LGTM badges) as requested by you

[AdamRJensen]

Just wanted to note that this is related to GitHub retiring LGTM (see #1550 for further details).

[AdamRJensen]

Thanks @ooprathamm

Could you also remove the line "exclude .lgtm.yml" in the file "MANIFEST.in" and the file .lgtm.yml.

[mikofski]

@ooprathamm a few more tasks to close this out:

• remove the line exclude .lgtm.yml in the file "MANIFEST.in"
• remove the file .lgtm.yml.
• add a note under documentation and add your name to contributors in what's new for 0.9.5

[ooprathamm]

@mikofski made the changes asked by you.