Bump knex from 0.16.3 to 0.19.5

Bumps [knex](https://github.com/tgriesser/knex) from 0.16.3 to 0.19.5.
- [Release notes](https://github.com/tgriesser/knex/releases)
- [Changelog](https://github.com/knex/knex/blob/master/CHANGELOG.md)
- [Commits](knex/knex@0.16.3...0.19.5)

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -97,7 +97,7 @@
     "helmet": "^3.15.0",
     "isomorphic-unfetch": "^3.0.0",
     "json-schema": "^0.2.3",
-    "knex": "^0.16.3",
+    "knex": "^0.19.5",
     "lodash": "^4.17.11",
     "next": "^7.0.2",
     "next-images": "^1.1.1",