fix: prefer system package rather than easy_install for getting pip

gimmes/pip

@@ -7,6 +7,6 @@ if ! has pip; then
 	if [[ "$OS" = "Darwin" ]]; then
 		curl -fsSL "https://bootstrap.pypa.io/get-pip.py" | python - --user
 	else
-		sudo easy_install pip
+		gimme_pkg python-pip || sudo easy_install pip
 	fi
 fi