Update rollup requirement to ^0.57.0 - #74

Sourced from rollup's changelog.

0.57.0

• Add option to preserve the module structure instead of bundling (#1922)
• Enable watch mode when code-splitting (#2035)
• Optionally pass CLI commands to config file (#1926)
• Option to add correct .toString tags to namespaces (#2041)
• Option and scripts to display performance timings (#2045)
• Fixes for exported or early accessed namespaces + improved namespace indentation (#2041)
• Include missing TypeScript dependencies (#1965)
• Add #_PURE annotation to frozen namespaces (#2044)
• Improve sourcemap and tree-shaking performance (#2052)
• Inline sourcemap lookups and make rollup smaller (#2055)
• Use updated magic-string types (#2057)
• [BREAKING] Revert class id preservation from #2025 (#2048)
• [BREAKING] Refactor missing export plugin hook (#1987)

0.56.5

• Preserve ids when deconflicting classes (#2025)
• Fix an issue with re-exported namespace imports (#2034)
• Prevent an infinite loop when binding member expressions (#1963)
• Convert code style via prettier (#2031)
• Fix links in documentation (#2026)

0.56.4

• Make rollup builds reproducible (#2024)
• Improve error handling for source maps (#2012)
• Properly handle SystemJS default exports without semicolons (#2019)
• Properly handle importing the same variable several times when code-splitting (#2020)
• Improve re-export tracing (#2021)
• Apply "prettier" on commit (#2017)
• Automatically clean up outdated tests (#2009)
• Add SystemJS output to form tests (#2022)
• Improve internal build configuration (#2016)

0.56.3

• Fix issues around default exports and module facades (#2001)
• Improve and fix internal chunk interface (#1994)
• Fix superfluous semicolons added after declarations (#1999)
• Improve code-splitting tests (#1990)

0.56.2

• Fix handling of reassigned default exports (#1975)
• Fix handling of renamed exports in entry points (#1977)
• Update internal TypeScript version (#1980)
• Omit compiled source files from published types (#1981)
• Fix example in readme file (#1984)
• Fix non-replaced dynamic imports in non-ESM output (#1985)

0.56.1

• Fix regression when rendering switch statements (#1971)

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