fix: fix semver vulnerability

[dangreen]

fixes #1019

[coveralls]

coverage: 89.531% (+0.005%) from 89.526% when pulling 244eb87 on fix-semver-vulnerability into 2f1df78 on master.

[nbouvrette]

@dangreen Is this going to be release in conventional-changelog soon? Right now the vulnerability is still present:

conventional-changelog@4.0.0
└─┬ conventional-changelog-core@5.0.2
  └─┬ conventional-changelog-writer@6.0.1
    └── semver@7.5.1