Improve global FAIL variables

test/tests/test_plugin_installation.sh

@@ -4,7 +4,7 @@ CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
 source $CURRENT_DIR/helpers.sh
 
-FAIL=false
+export FAIL=false
 
 test_plugin_installation() {
 	set_tmux_conf_helper <<- HERE

test/tests/test_plugin_sourcing.sh

@@ -4,7 +4,7 @@ CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
 source $CURRENT_DIR/helpers.sh
 
-FAIL=false
+export FAIL=false
 
 check_binding_defined() {
     local binding=$1