VERSION, params: start 1.7.3 release cycle

VERSION

@@ -1 +1 @@
-1.7.2
+1.7.3

params/version.go

@@ -23,8 +23,8 @@ import (
 const (
 	VersionMajor = 1          // Major version component of the current release
 	VersionMinor = 7          // Minor version component of the current release
-	VersionPatch = 2        // Patch version component of the current release
+	VersionPatch = 3          // Patch version component of the current release
-	VersionMeta  = "stable" // Version metadata to append to the version string
+	VersionMeta  = "unstable" // Version metadata to append to the version string
 )
 
 // Version holds the textual version string.