Application superstructure (or supersingleton, if you want).

Got rid of context thing which misleads due to existance of stdlib's
context package.

Also fixed golangci-lint configuration.

Fixes #20.

domains/indexpage/exported.go

@@ -25,15 +25,15 @@
 package indexpage
 
 import (
-	"go.dev.pztrn.name/fastpastebin/internal/context"
+	"go.dev.pztrn.name/fastpastebin/internal/application"
 )
 
-var ctx *context.Context
+var app *application.Application
 
 // New initializes pastes package and adds necessary HTTP and API
 // endpoints.
-func New(cc *context.Context) {
-	ctx = cc
+func New(cc *application.Application) {
+	app = cc
 
-	ctx.Echo.GET("/", indexGet)
+	app.Echo.GET("/", indexGet)
 }

domains/indexpage/indexpage.go

@@ -37,8 +37,8 @@ import (
 // Index of this site.
 func indexGet(ectx echo.Context) error {
 	// We should check if database connection available.
-	dbConn := ctx.Database.GetDatabaseConnection()
-	if ctx.Config.Database.Type != flatfiles.FlatFileDialect && dbConn == nil {
+	dbConn := app.Database.GetDatabaseConnection()
+	if app.Config.Database.Type != flatfiles.FlatFileDialect && dbConn == nil {
 		//nolint:wrapcheck
 		return ectx.Redirect(http.StatusFound, "/database_not_available")
 	}