feat: Fabric 4.20 spec update (#41)

Author: thogarty

Makefile.fabricv4

@@ -3,7 +3,7 @@
 include Makefile
 
 PACKAGE_NAME=fabricv4
-SPEC_BASE_URL:=https://api.swaggerhub.com/apis/equinix-api/fabric/4.18
+SPEC_BASE_URL:=https://api.swaggerhub.com/apis/equinix-api/fabric/4.20
 SPEC_ROOT_FILE:=swagger.yaml
 
 QUALIFIED_PACKAGE_NAME=equinix.services.${PACKAGE_NAME}