PyInstaller: Enable to build stand-alone executables

Usage: After installing Ryu (on virtualenv is better), build a
ryu-manager executable as following:
   $ pip install PyInstaller==3.1.1
   $ cd tools/
   $ pyinstaller ryu-manager.spec
   $ ./dist/ryu-manager

Note: PyInstaller==3.2 may have a bug of str encoding, please use
Pyinstaller==3.1.1 instead.
   https://github.com/pyinstaller/pyinstaller/issues/1976

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

tools/ryu-manager.spec

@@ -0,0 +1,28 @@
+# -*- mode: python -*-
+
+block_cipher = None
+
+
+a = Analysis(['../bin/ryu-manager'],
+             pathex=['../ryu'],
+             binaries=None,
+             datas=None,
+             hiddenimports=['ryu.controller.ofp_handler'],
+             hookspath=[],
+             runtime_hooks=[],
+             excludes=[],
+             win_no_prefer_redirects=False,
+             win_private_assemblies=False,
+             cipher=block_cipher)
+pyz = PYZ(a.pure, a.zipped_data,
+          cipher=block_cipher)
+exe = EXE(pyz,
+          a.scripts,
+          a.binaries,
+          a.zipfiles,
+          a.datas,
+          name='ryu-manager',
+          debug=False,
+          strip=False,
+          upx=True,
+          console=True)