Adds missing OpenAPI configuration file

Also locks the tools versions and launches them from the packages
installed by the go mod. Otherwise, they would have to be manually
installed beforehand.

internal/api/api.cfg.yaml

@@ -0,0 +1,6 @@
+package: api
+generate:
+  echo-server: true
+  models: true
+  embedded-spec: true
+output: server.gen.go

internal/api/impl.go

@@ -8,7 +8,7 @@ import (
 	"github.com/labstack/echo/v4"
 )
 
-//go:generate oapi-codegen --config=api.cfg.yaml ../../docs/openapi.yaml
+//go:generate go run github.com/deepmap/oapi-codegen/v2/cmd/oapi-codegen@v2.1.0 --config=api.cfg.yaml ../../docs/openapi.yaml
 
 type ServerImpl struct {
 	Dal dal.DAL

internal/dal/dal.go

@@ -9,4 +9,4 @@ type DAL interface {
 	Banks() (entity.Banks, error)
 }
 
-//go:generate mockgen -destination=../mock/mock_dal.gen.go -package=mock . DAL
+//go:generate go run go.uber.org/mock/mockgen@latest -destination=../mock/mock_dal.gen.go -package=mock . DAL

tools.go

@@ -1,7 +1,7 @@
 //go:build tools
 // +build tools
 
-package main
+package tools
 
 import (
 	_ "github.com/deepmap/oapi-codegen/v2/cmd/oapi-codegen"