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/dbnotavailable/exported.go

@@ -25,16 +25,16 @@
 package dbnotavailable
 
 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("/database_not_available", dbNotAvailableGet)
-	ctx.Echo.GET("/database_not_available/raw", dbNotAvailableRawGet)
+	app.Echo.GET("/database_not_available", dbNotAvailableGet)
+	app.Echo.GET("/database_not_available/raw", dbNotAvailableRawGet)
 }