build: bump semantic-release from 15.1.5 to 15.4.1

[dependabot-preview]

Bumps semantic-release from 15.1.5 to 15.4.1.

Release notes

Sourced from semantic-release's releases.

v15.4.1

15.4.1 (2018-05-09)

Bug Fixes

• use git rev-parse origin/${branch} to verify origin head (d7081fa)

v15.4.0

15.4.0 (2018-05-08)

Features

• set tag author and committer name/email (61d7d38)

v15.3.2

15.3.2 (2018-05-08)

Bug Fixes

• correct git merge-base error code handling (4352144)

v15.3.1

15.3.1 (2018-05-05)

Bug Fixes

• package: update cosmiconfig to version 5.0.0 (349b2e8)

v15.3.0

15.3.0 (2018-05-04)

Features

• log git error message when authentication verification fails (cd9f2bd)

v15.2.0

15.2.0 (2018-05-01)

... (truncated)

Commits

• d7081fa fix: use git rev-parse origin/${branch} to verify origin head
• 61d7d38 feat: set tag author and committer name/email
• 4352144 fix: correct git merge-base error code handling
• 20245b7 docs: add comment about publishing with ssh keys
• 349b2e8 fix(package): update cosmiconfig to version 5.0.0
• 1ed466e ci: run test on Node.js 10
• f0f325d docs: add link to shareable configs and plugins list
• f3e4991 chore(package): update xo to version 0.21.0
• cd9f2bd feat: log git error message when authentication verification fails
• d1c3ad0 docs: issue templates order
• Additional commits viewable in compare view

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🎉 This PR is included in version 1.3.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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