fix(deps): update gatsby monorepo

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change	References
gatsby	dependencies	patch	2.0.115 -> 2.0.118	source
gatsby-plugin-offline	dependencies	patch	2.0.22 -> 2.0.23	source

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Release Notes

gatsbyjs/gatsby

v2.0.118

Compare Source

v2.0.117

Compare Source

v2.0.116

Compare Source

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