Add version scoped url

golang/go#35732

It looks like our install instructions fall into this [pseudo-version](https://golang.org/cmd/go/#hdr-Pseudo_versions)
trap mentioned in the above issue. This adds the `v3` scope to the url
and it updated the bump script to make sure that the number stays up to
date.

.bumpversion.cfg

@@ -8,3 +8,15 @@ serialize =
 
 [bumpversion:file:version.go]
 
+[bumpversion:file:README.md]
+parse = (?P<major>\d+)
+serialize = {major}
+search = github.com/recurly/recurly-client-go/v{current_version}
+replace = github.com/recurly/recurly-client-go/v{new_version}
+
+[bumpversion:file:go.mod]
+parse = (?P<major>\d+)
+serialize = {major}
+search = github.com/recurly/recurly-client-go/v{current_version}
+replace = github.com/recurly/recurly-client-go/v{new_version}
+

README.md

@@ -11,14 +11,14 @@ Documentation for the HTTP API and example code can be found [on our Developer H
 Install using `go get`:
 
 ```
-go get -u github.com/recurly/recurly-client-go
+go get -u github.com/recurly/recurly-client-go/v3
 ```
 
 import with:
 
 ```go
 import (
-    "github.com/recurly/recurly-client-go"
+    "github.com/recurly/recurly-client-go/v3"
 )
 ```
 

go.mod

@@ -1,3 +1,3 @@
-module github.com/recurly/recurly-client-go
+module github.com/recurly/recurly-client-go/v3
 
 go 1.12

scripts/bump

@@ -7,5 +7,5 @@ if [ "$1" == "--next-version" ]; then
 elif [ "$1" == "--this-version" ]; then
   grep current_version .bumpversion.cfg | awk -F" = " '{print $2}'
 else
-  bump2version "$@"
-fi
+  bump2version --allow-dirty "$@"
+fi