Reduced & updated dependencies.

By default, messages larger than 2.000 characters (sent via tells) get sent via slaves, if these exist.
Fixes #3

update.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+git pull
+
+PYTHON_BINARY=python3
+if ! [ -x "$(command -v $PYTHON_BINARY)" ]; then
+  PYTHON_BINARY=python
+fi
+
+$PYTHON_BINARY --version
+
+# Ensure virtualenv is present. This is not always the case
+$PYTHON_BINARY -m pip install virtualenv --user
+
+# Create and activate the virtualenv. This can be done even if it already exists
+# and will ensure setuptools, wheel and pip are up to date
+$PYTHON_BINARY -m virtualenv venv
+source venv/bin/activate
+
+# From there on we use 'pip' and 'python' (refers to versions in the virtualenv)
+pip install -r requirements.txt
+
+echo "Update completed."