[Tests] clean up .nvmrc after nvm-exec test

test/fast/Running 'nvm-exec' should display required node version

@@ -4,7 +4,9 @@ set -x
 : nvm.sh
 \. ../../nvm.sh
 
-die () { echo "$@" ; rm .nvmrc ; exit 1; }
+cleanup() { rm -f .nvmrc; }
+
+die () { echo "$@" ; cleanup ; exit 1; }
 
 NVM_TEST_VERSION=v0.42
 
@@ -19,3 +21,5 @@ No NODE_VERSION provided; no .nvmrc file found";
 
 # Skip install, we want to test the error message
 [ "${EXPECTED}" = "${OUTPUT}" ] || die "expected >${EXPECTED}<, got >${OUTPUT}<"
+
+cleanup