Ensure undercover.el is loaded first in tests

undercover.el needs to be set up before loading the files for which
coverage is to be computed.

Makefile

@@ -14,7 +14,7 @@ test: clean
 	cask exec buttercup -L . tests
 
 test-with-flx: clean
-	cask exec buttercup -L . tests tests-with-flx-ido
+	cask exec buttercup -l tests/setup-undercover.el -L . tests tests-with-flx-ido
 
 all-tests: test test-with-flx
 

tests/setup-undercover.el

@@ -0,0 +1,3 @@
+(require 'undercover)
+(undercover "*.el"
+            (:exclude "test-*.el"))

tests/test-ido-completing-read+.el

@@ -1,9 +1,5 @@
 ;;; -*- lexical-binding: t -*-
 
-(require 'undercover)
-(undercover "*.el"
-            (:exclude "test-*.el"))
-
 (require 'ido)
 (require 'minibuf-eldef)
 (require 'ido-completing-read+)