* cmd/mediaapi-integration-tests: Add foundation for testing

* common/test: Add some server init and client request utilities

* common/test/client: Handle timed out requests for tests that passed

* cmd/syncserver-integration-tests: Port to new common/test infra

* common/test/client: Remove stray debug print

* cmd/mediaapi-integration-tests: Simplify slice initialisation

* cmd/mediaapi-integration-tests: Simplify getMediaURL argument

* cmd/mediaapi-integration-tests: Make startMediaAPI return listen address

* common/test/client: Fix uninitialised LastRequestErr

* common/test/server: Remove redundant argument

* common/test/server: Add StartProxy to create a reverse proxy

* cmd/mediaapi-integration-tests: Add proxies in front of servers

This is needed so that origins can be correctly configured and used for
remote media.

* travis: Enable media API integration tests

* travis: Build the client-api-proxy for media tests

* common/test/client: Don't panic on EOF in CanonicalJSONInput

* cmd/mediaapi-integration-tests: Add upload/download/thumbnail tests

* mediaapi/thumbnailer: Store thumbnail according to requested size

* cmd/mediaapi-integration-tests: Add totem.jpg test file

* cmd/client-api-proxy: Optionally listen for HTTPS

* common/test/client: Do not verify TLS certs for testing

We will commonly use self-signed certs.

* cmd/mediaapi-integration-tests: Make HTTPS requests

* cmd/mediaapi-integration-tests: Log size and method for thumbnails

* mediaapi/thumbnailer: Factor out isThumbnailExists

Appease gocyclo^w^w simplify

* mediaapi/thumbnailer: Check if request is larger than original

* travis: Install openssl and generate server.{crt,key}

* cmd/mediaapi-integration-tests: Add valid dynamic thumbnail test

* cmd/mediaapi-integration-tests: Document state of tests

* cmd/mediaapi-integration-tests: Test remote thumbnail before download

This ordering also exercises the cold cache immediate generation of a
size configured for pregeneration.

* travis: Explain openssl key+cert generation

* common/test/server: Clarify postgresContainerName