Pass shellcheck, more specs are handled, preserve function whitespace

This closes #49.

tests/fail-not-set

@@ -3,10 +3,10 @@ cd "${0%/*}" || exit 1
 . ../run-tests
 
 unset __NO_SUCH_VAR
-POPULATED="words"
-EMPTY=""
-arguments=(--fail-not-set)
-returnCode=1
+export POPULATED="words"
+export EMPTY=""
+export arguments=(--fail-not-set)
+export returnCode=1
 
 template() {
     cat <<EOF
@@ -15,10 +15,6 @@ Empty: {{EMPTY}};
 Unset: {{__NO_SUCH_VAR}};
 EOF
 }
-expected() {
-    cat <<EOF
-ERROR: Environment variable not set: __NO_SUCH_VAR
-EOF
-}
+export expected=$'ERROR: Environment variable not set: __NO_SUCH_VAR\n'
 
 runTest