Implement grammar and config to navigate by speech

psConfig/exercise/aharter.conf

+[main]
+startdb=30;
+uttdb=35;
+silence=400;
+timeout=8;
+openDeviceDirectly=yes;
+
+[pocketsphinxinstance]
+name=confirm;
+jsgf=../../psGrammar/confirm/confirm.jsgf;
+rostopic=/speechrec/psa/confirm;
+bestpath=no;
+autoload=yes;
+
+[pocketsphinxinstance]
+name=speech_nav;
+jsgf=../../psGrammar/exercise/aharter.jsgf;
+rostopic=/speechrec/psa/speech_nav;
+bestpath=no;
+autoload=yes;
\ No newline at end of file

psGrammar/exercise/aharter.jsgf

+#JSGF V1.0;
+grammar ToBI_commands;
+public <statement> = (tobi | tiago) <command>;
+<command> = (go forward <num> (meter | meters)) | (turn <dir>) | stop;
+<num> = one | two;
+<dir> = right | left | back;
+