Fix test environments

packaging/debian/rules

 	make install PREFIX=/usr DESTDIR=debian/tmp
 
 override_dh_auto_test:
-	make test SHELLFU_PATH=$(shell pwd)/src
+	make test \
+		SHELLFU_PATH=$(shell pwd)/debian/tmp/usr/share/shellfu/include-bash

packaging/template.spec

 
 %check
 make test \
-    "PATH=%{buildroot}%{_bindir}:$PATH" \
-    "SHELLFU_DIR=%{buildroot}%{_datadir}/%{name}"
+    SHELLFU_PATH=%{buildroot}/%{_datadir}/shellfu/include-bash
 
 %files
 %doc %{_docdir}/%{name}/README.md