tests: Set EDITOR=: and VISUAL=: globally

This way we don't have to remember to set it for each test; and
if we forget, we won't cause interactive editors to be spawned
for non-interactive tests.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

t/test-lib.sh

@@ -9,6 +9,8 @@ LC_ALL=C
 PAGER=cat
 TZ=UTC
 export LANG LC_ALL PAGER TZ
+EDITOR=:
+VISUAL=:
 unset AUTHOR_DATE
 unset AUTHOR_EMAIL
 unset AUTHOR_NAME
@@ -30,6 +32,7 @@ unset SHA1_FILE_DIRECTORIES
 unset SHA1_FILE_DIRECTORY
 export GIT_AUTHOR_EMAIL GIT_AUTHOR_NAME
 export GIT_COMMITTER_EMAIL GIT_COMMITTER_NAME
+export EDITOR VISUAL
 
 # Each test should start with something like this, after copyright notices:
 #