Release v5.1.0

Changes

• CI build for ghc-8.8.3 by @newhoggy
• Merge pull request #32 from haskell-works/ci-build-for-ghc-8.8.3 CI build for ghc-8.8.3 by @newhoggy
• Update CCI by @AlexeyRaga
• Upgrade to hackage@1.4.1 by @newhoggy
• Merge pull request #33 from haskell-works/upgrade-to-hackage@1.4.1 Upgrade to hackage@1.4.1 by @newhoggy
• Introduce merge point by @newhoggy
• Merge pull request #34 from haskell-works/use-released-version-of-merge-point Introduce merge point by @newhoggy
• Support ghc-8.10.1 by @newhoggy
• Merge pull request #35 from haskell-works/support-ghc-8.10.1 Support ghc-8.10.1 by @newhoggy
• New version 5.1.0 by @newhoggy