Implement Cobra CLI tooling, Viper config tooling (#336)

* start pulling out + replacing urfave and config

* replace many many instances of config

* move more stuff => viper

* properly remove urfave

* move some flags to root command

* add testrig commands to root

* alias config file keys

* start adding cli parsing tests

* reorder viper init

* remove config path alias

* fmt

* change config file keys to non-nested

* we're more or less in business now

* tidy up the common func

* go fmt

* get tests passing again

* add note about the cliparsing tests

* reorganize

* update docs with changes

* structure cmd dir better

* rename + move some files around

* fix dangling comma

internal/processing/timeline.go

@@ -21,10 +21,13 @@ package processing
 import (
 	"context"
 	"fmt"
-	"github.com/sirupsen/logrus"
 	"net/url"
 
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/viper"
+
 	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
@@ -39,17 +42,20 @@ func (p *processor) packageStatusResponse(statuses []*apimodel.Status, path stri
 
 	// prepare the next and previous links
 	if len(statuses) != 0 {
+		protocol := viper.GetString(config.Keys.Protocol)
+		host := viper.GetString(config.Keys.Host)
+
 		nextLink := &url.URL{
-			Scheme:   p.config.Protocol,
-			Host:     p.config.Host,
+			Scheme:   protocol,
+			Host:     host,
 			Path:     path,
 			RawQuery: fmt.Sprintf("limit=%d&max_id=%s", limit, nextMaxID),
 		}
 		next := fmt.Sprintf("<%s>; rel=\"next\"", nextLink.String())
 
 		prevLink := &url.URL{
-			Scheme:   p.config.Protocol,
-			Host:     p.config.Host,
+			Scheme:   protocol,
+			Host:     host,
 			Path:     path,
 			RawQuery: fmt.Sprintf("limit=%d&min_id=%s", limit, prevMinID),
 		}