Train from the command line

The files in the `cli` directory allow you to train wake words
from the command line without needing to use the Jupyter notebook
or a web browser.  Basically, the logic from the notebook has been
placed in separate shell scripts and python files wrapped by 3 high-level
scripts that do the following:

* setup_python_venv: Creates a Python virtual environment with all the
packages needed to train.  The venv is created in the container's /data
directory and is therefore stored on the host, not in the container's root
docker volume.

* setup_training_datasets: Downloads, extracts and converts the MIT RIR,
FMA, Audioset and Negative training reference datasets.  Also stored in /data.

* train_wake_word: Generates the wake word samples, augments them with the
audio from the training datasets, and finally runs the microwakeword training.
The resulting model tflite and json files are placed in the /data/output
directory.

See the README.md file for much more information.

cli/.bashrc

@@ -0,0 +1,135 @@
+# ~/.bashrc: executed by bash(1) for non-login shells.
+# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
+# for examples
+
+# If not running interactively, don't do anything
+[ -z "$PS1" ] && return
+
+# don't put duplicate lines in the history. See bash(1) for more options
+# ... or force ignoredups and ignorespace
+HISTCONTROL=ignoredups:ignorespace
+
+# append to the history file, don't overwrite it
+shopt -s histappend
+
+# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
+HISTSIZE=1000
+HISTFILESIZE=2000
+
+# check the window size after each command and, if necessary,
+# update the values of LINES and COLUMNS.
+shopt -s checkwinsize
+
+# make less more friendly for non-text input files, see lesspipe(1)
+[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"
+
+# set variable identifying the chroot you work in (used in the prompt below)
+if [ -z "$debian_chroot" ] && [ -r /etc/debian_chroot ]; then
+    debian_chroot=$(cat /etc/debian_chroot)
+fi
+
+# set a fancy prompt (non-color, unless we know we "want" color)
+case "$TERM" in
+    xterm-color) color_prompt=yes;;
+esac
+
+# uncomment for a colored prompt, if the terminal has the capability; turned
+# off by default to not distract the user: the focus in a terminal window
+# should be on the output of commands, not on the prompt
+#force_color_prompt=yes
+
+if [ -n "$force_color_prompt" ]; then
+    if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
+	# We have color support; assume it's compliant with Ecma-48
+	# (ISO/IEC-6429). (Lack of such support is extremely rare, and such
+	# a case would tend to support setf rather than setaf.)
+	color_prompt=yes
+    else
+	color_prompt=
+    fi
+fi
+
+if [ "$color_prompt" = yes ]; then
+    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
+else
+    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
+fi
+unset color_prompt force_color_prompt
+
+# If this is an xterm set the title to user@host:dir
+case "$TERM" in
+xterm*|rxvt*)
+    PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
+    ;;
+*)
+    ;;
+esac
+
+# enable color support of ls and also add handy aliases
+if [ -x /usr/bin/dircolors ]; then
+    test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
+    alias ls='ls --color=auto'
+    #alias dir='dir --color=auto'
+    #alias vdir='vdir --color=auto'
+
+    alias grep='grep --color=auto'
+    alias fgrep='fgrep --color=auto'
+    alias egrep='egrep --color=auto'
+fi
+
+# some more ls aliases
+alias ll='ls -alF'
+alias la='ls -A'
+alias l='ls -CF'
+
+# Alias definitions.
+# You may want to put all your additions into a separate file like
+# ~/.bash_aliases, instead of adding them here directly.
+# See /usr/share/doc/bash-doc/examples in the bash-doc package.
+
+if [ -f ~/.bash_aliases ]; then
+    . ~/.bash_aliases
+fi
+
+# enable programmable completion features (you don't need to enable
+# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
+# sources /etc/bash.bashrc).
+#if [ -f /etc/bash_completion ] && ! shopt -oq posix; then
+#    . /etc/bash_completion
+#fi
+
+if [ -f /data/.bashrc ]; then
+    . /data/.bashrc
+fi
+
+if ! mountpoint -q /data ; then
+    cat <<-EOF >&2
+    =======================================================
+    WARNING: The /data directory is NOT mounted.
+    Running the training process without /data mounted
+    could add over 140Gb of python packages and training
+    files to this container's storage which is probably
+    NOT what you want.
+
+    You should remove this container and re-create it with
+    a 'docker run' option like '-v <host_work_dir>:/data'
+    making sure the host directory is on a device that has
+    enough free space.
+    =======================================================
+EOF
+fi
+
+if [ -d /data/.venv ]; then
+    . /data/.venv/bin/activate
+else
+    cat <<-EOF >&2
+    =======================================================
+    WARNING: A python virtual environment wasn't found
+    at /data/.venv.  You'll need to run 'setup_python_venv'
+    before you'll be able to use this container for
+    training.
+    =======================================================
+EOF
+
+fi
+alias venv='[ -d /data/.venv ] && source /data/.venv/bin/activate || echo "/data/.venv does not exist yet"'