fix: PATH update for non-fish shells

Checks PATH variable for existing inclusion of shims
for shells other than fish.

See PR #430

Author: keikoro

bin/pyenv-virtualenv-init

@@ -95,8 +95,10 @@ EOS
   ;;
 * )
   cat <<EOS
+if [[ ":$PATH:" != *"${PYENV_VIRTUALENV_ROOT:-${PYENV_VIRTUALENV_INSTALL_PREFIX}}/shims"* ]]; then
 export PATH="${PYENV_VIRTUALENV_ROOT:-${PYENV_VIRTUALENV_INSTALL_PREFIX}}/shims:\${PATH}";
 export PYENV_VIRTUALENV_INIT=1;
+fi
 EOS
   ;;
 esac