Fix python3-ism with byte v. str

README.md

@@ -43,8 +43,14 @@ signer = sign_m2crypto.M2CryptoSigner(
 device = adb_commands.AdbCommands.ConnectDevice(
     rsa_keys=[signer])
 # Now we can use Shell, Pull, Push, etc!
-for i in xrange(10):
-  print device.Shell('echo %d' % i)
+for i in range(10):
+  print(device.Shell('echo %d' % i))
+
+# Want to check the kernel version? Do this.
+print(device.Shell('uname -a'))
+
+# Want to check some properties? Do this.
+print(device.Shell('getprop | grep dalvik'))
 ```
 
 ### Pros

adb/adb_protocol.py

@@ -277,6 +277,10 @@ def Connect(cls, usb, banner=b'notadb', rsa_keys=None, auth_timeout_ms=100):
       InvalidResponseError: When the device does authentication in an
           unexpected way.
     """
+    # In py3, convert unicode to bytes. In py2, convert str to bytes.
+    # It's later joined into a byte string, so in py2, this ends up kind of being a no-op.
+    if isinstance(banner, str):
+        banner = bytearray(banner, 'utf-8')
     msg = cls(
         command=b'CNXN', arg0=VERSION, arg1=MAX_ADB_DATA,
         data=b'host::%s\0' % banner)