Bump cross-env from 5.2.1 to 7.0.3

Bumps cross-env from 5.2.1 to 7.0.3.

Release notes

Sourced from cross-env's releases.

v7.0.3

7.0.3 (2020-12-01)

Bug Fixes

• add maintenance mode notice (fe80c84)

v7.0.2

7.0.2 (2020-03-05)

Reverts

• Revert "fix: signal handling (#227)" (2a1f44c), closes #227

v7.0.1

7.0.1 (2020-03-03)

Bug Fixes

• signal handling (#227) (8a9cf0e)

v7.0.0

7.0.0 (2020-01-25)

Features

• update dependencies (#223) (4ec6f40)

BREAKING CHANGES

• Drop Node 8 support

v6.0.3

6.0.3 (2019-10-02)

Bug Fixes

• do not compile anything (67f21c3)

v6.0.2

6.0.2 (2019-10-01)

... (truncated)

Commits

• bb0287b docs: add dsbert as a contributor (#260)
• 6f571e1 docs: Update README.md (#259)
• fe80c84 fix: add maintenance mode notice
• 07a91d6 chore: Update validate.yml (#255)
• b2a610b chore(validate): Filter out all-contributors branches (#254)
• 54eec15 chore: only run push jobs on releasable branches (#253)
• 8edd827 chore: Switch to GitHub Actions (#251)
• ed844af docs: add devuxer as a contributor (#241)
• bddb4d5 docs: add multi vars example to README (#240)
• 9a5a9bd chore: Only release on original repo (#237)
• Additional commits viewable in compare view