Error pasting bold text from google docs

[nelsonpecora]

Description

Sometime in the recent past, Google Docs changed how it does bolded text (from font-weight: bold to font-weight: 700). This means pasted bold text is not being caught by Medium-Editor's paste extension.

I'm making a pull request to address this issue.

Steps to reproduce

1. Create bolded text in google docs
2. Paste (via ctrl+v, edit menu, or right click) into medium-editor

Expected behavior: Bold formatting should be preserved

Actual behavior: Bold formatting is not preserved (note: italics are fine)

Link to an example: demo page

Versions

• medium-editor: 5.21.0
• browser: chrome 51
• OS: macOS 10.11.6