tox: Update PyInstaller to 3.2

- Even the “main” script is now byte-compiled
- The manual is on readthedocs.io now
- On installation try to compile the bootloader if there is none for the
  current plattform
- (Unix) Use objcopy to create a valid ELF file
- (Linux): Compile with _FORTIFY_SOURCE
- New, updated and fixed hooks: CherryPy, Cryptography, enchant,
  gi.repository.GdkPixbuf, gst, Lib2to3, PyQt4, PyQt5, PySide, SciPy,
  sphinx, sqlalchemy, traitlets, wx.lib.pubsub
- For windowed mode add isatty() for our dummy NullWriter
- Suppress “Failed to execute script” in case of SystemExit
- Do not apply Upx compressor for bootloader files
- Fix absolute path for lib used via ctypes
- (OSX) Fix binary cache on NFS
- (Windows) Fix message in grab_version
- (Windows) Fix wrong icon paramter in Windows example
- (Windows) Fix win32 unicode handling
- (Windows) Fix unnecessary rebuilds caused by rebuilding winmanifest
- (Cygwin) Fix finding the Python library for Cygwin 64-bit
- (OSX) Fix compilation issue
- (Windows) No longer bundle pefile, use package from for windows
- (Windows) Provide a more robust means of executing a Python script
- AIX fixes.
- Update waf to version 1.8.20
- Fix excludedimports, more predictable order how hooks are applied
- Internal impovements and code clean-up
- Clean-ups fixes and improvements for the test suite

tox.ini

@@ -213,7 +213,7 @@ basepython = python3
 -skip_install = true
 deps =
     -r{toxinidir}/requirements.txt
-    PyInstaller==3.1.1
+    PyInstaller==3.2
 commands =
     {envpython} scripts/link_pyqt.py --tox {envdir}
     {envbindir}/pyinstaller --noconfirm misc/qutebrowser.spec