Use OCI API for Oracle providers (#42)

* Bump go-swagger to 0.25.0 and regenerate client

This results in the removal of some old concepts such as 'calls' and 'logs' (which I think are long disused and date from the v1 days?)

* Revendor latest versions of dependencies

* First pass at Apps shim

* Add tests for Apps shim

Mock out OCI SDK backend for this

* Change Oracle user provider to use OCI shim

Apps only for now. This respects the existing config precedence of env vars > Fn CLI context > OCI config file

* Bump to Go 1.14

* Don't export appsShim struct

* First pass at Fns shim

* Add tests for Fns shim

* Add Triggers shim

These are just stubbed out as Oracle Functions doesn't support Triggers

* Re-add 'Signer' to user provider

This is used by the invoke code in Fn CLI, so it's required. Fortunately, we can simply extract the key information from the OCI config provider we've constructed.

* Switch Oracle IP provider to use OCI API shim

Also, allow user provider to derive API endpoint entirely from OCI config

* Switch Oracle CS provider to use OCI shim

* Respect disableCerts in OCI shim

* Cleanup

* Don't pass nil contexts to OCI client

* Add basic useragent prefix

* Final cleanup

.circleci/config.yml

@@ -2,7 +2,7 @@ version: 2
 jobs:
   build:
     docker:
-      - image: circleci/golang:1.10
+      - image: circleci/golang:1.14
     working_directory: /go/src/github.com/fnproject/fn_go
     steps:
       - checkout