+semver: upgrade to net5.0 (#1390)

* breaking upgrade base build image to net5.0

* add make and build tools to image

* fix code broken after net5.0 upgrade

* fix warnings

* fix tests and line endings

* upgrade dotnet test and coverages packages

* update circle build image

* removed rafty and updated more packages

* bring back develop

* rename authorisation to authorization

docs/index.rst

@@ -26,7 +26,7 @@ Thanks for taking a look at the Ocelot documentation. Please use the left hand n
    features/servicefabric
    features/kubernetes
    features/authentication
-   features/authorisation
+   features/authorization
    features/websockets
    features/administration
    features/ratelimiting
@@ -41,7 +41,6 @@ Thanks for taking a look at the Ocelot documentation. Please use the left hand n
    features/middlewareinjection
    features/loadbalancer
    features/delegatinghandlers
-   features/raft
    features/errorcodes
 
 .. toctree::