Instruction to update .gitignore is incorrect

[Deborah-Digges]

Issue Summary

In CONTRIBUTING.md, the following command is given to add sendgrid.env to .gitignore:

echo "sendgrid.env" >> .gitignore

However, this results in an incorrect .gitignore file which looks like this after running the command:

open_source_library_data.egg-info/

README.txtsendgrid.env

Steps to Reproduce

1. Run the command echo "sendgrid.env" >> .gitignore
2. cat .gitignore | tail

Actual output

README.txtsendgrid.env

Expected output

README.txt
sendgrid.env

Technical details:

• Python Version: 3.6.3
• Browser/OS: Chrome/MacOS
• Database/Version: mysql Ver 8.0.12 for macos10.13 on x86_64 (MySQL Community Server - GPL)