chore(dev): prepare development cycle (#538)

Prepare the plugin for the 2.1.5 development cycle and pre-release builds.

Signed-off-by: Ryan Johnson <ryan.johnson@broadcom.com>

Author: tenthirtyam

version/version.go

@@ -7,8 +7,8 @@ package version
 import "github.com/hashicorp/packer-plugin-sdk/version"
 
 var (
-	Version           = "2.1.4"
-	VersionPrerelease = ""
+	Version           = "2.1.5"
+	VersionPrerelease = "dev"
 	VersionMetadata   = ""
 	PluginVersion     = version.NewPluginVersion(Version, VersionPrerelease, VersionMetadata)
 )