refactor: http interfaces (#114)

* implement custom http handler interface

* implement trace_id

* normalize http method spacing for consistent logs

* fix failing test

* fix linter errors

* cleanup old dead code

* more route cleanup

* cleanup some inconsistent errors

* update and generate code

* make taskfile more consistent

* update task calls

* run tidy

* drop `@` tag for version

* use relative paths

* tidy

* fix auto-setting variables

* update build paths

* add contributing guide

* tidy

backend/pkgs/server/middleware.go

@@ -0,0 +1,38 @@
+package server
+
+import (
+	"net/http"
+	"strings"
+)
+
+type Middleware func(Handler) Handler
+
+// wrapMiddleware creates a new handler by wrapping middleware around a final
+// handler. The middlewares' Handlers will be executed by requests in the order
+// they are provided.
+func wrapMiddleware(mw []Middleware, handler Handler) Handler {
+
+	// Loop backwards through the middleware invoking each one. Replace the
+	// handler with the new wrapped handler. Looping backwards ensures that the
+	// first middleware of the slice is the first to be executed by requests.
+	for i := len(mw) - 1; i >= 0; i-- {
+		h := mw[i]
+		if h != nil {
+			handler = h(handler)
+		}
+	}
+
+	return handler
+}
+
+// StripTrailingSlash is a middleware that will strip trailing slashes from the request path.
+//
+// Example: /api/v1/ -> /api/v1
+func StripTrailingSlash() Middleware {
+	return func(h Handler) Handler {
+		return HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
+			r.URL.Path = strings.TrimSuffix(r.URL.Path, "/")
+			return h.ServeHTTP(w, r)
+		})
+	}
+}