* Add a wider diversity of `gui` options
Although I know we want to remain less tied to the GraphQL Playground
GUI options, we definitely want to support a wider variety of options to
be passed in. This adds support for specifying partial options either
statically or dynamically for the gui, which can be extended to allow
for a wider array of guis than only GraphQL playground.
* Add boolean option and configuration for tabs
* move gui setting into ApolloServer Constructor
* document playground configuration in the constructor
* update playground types and fixed micro + koa integrations
* change gui to playground
* docs: change gui to playground
* fix logic for playground creation
* add cors option to apollo-server's constructor
* docs: add cors option to costructor for apollo-server
* expose CorsOptions from vanilla and express integrations
* Update apollo-server.md
The package.json requires a start script, copying as is gives an error in now CLI: `> Error! Missing `start` (or `now-start`) script in `package.json`. See: https://docs.npmjs.com/cli/start`
* change logging to metrics and add section on Engine
* add to the migration guide
* address feedback and add clarity around logFunction
* address feedback for migration guide
* core: return response object from runHttpQuery
* core: change gqlResponse to graphqlResponse and add custom RequestInit type
* core: add cache-control headers based on the calcualted maxAge
* core: add extensions check during cache-control header creation
* core: create headers when cacheControl is not enabled otherwise pass through extensions
* express: initial tests of CDN cach-contol headers
* core: fixed tests with applyMiddleware and pass cacheControl config
* core: cache hint fixes, ignore when no maxAge, and check for rootKeys
* core: check for hints of length 0
* core: node 10 fails file upload test for some stream reason
* docs: add cdn caching section to features
* add space after // in comments
* fix feedback: proxy alignment and response creation
Adds cache-control toggles for http header calculation and stripping out
the cache control extensions from the respose.
Brings the default calculation of headers in line with the proxy.
* fix links in comments
* fix tests with null dereference
* update cdn docs and migration guide to include latest cdn configuration
* add not for engine migration to set engine to false
* add engine set to false in migration guide
* express: fixed tests
* address feedback to use omit and documentation
* docs: cdn caching is alternative to full response caching
* add back epipe check in upload tests
