Add wxPython dependency check in install program.

src/install.sh

@@ -60,7 +60,11 @@ error_exit () {
 	printf "      for more informations.\n"
 	printf "      Below is an excerpt of the last 10 lines:\n"
 	printf "\n"
-	tail "${LOGFILE}"
+	echo ">>> ..."
+	tail "${LOGFILE}" | while read line
+	do
+		echo ">>> $line"
+	done
 
 	# uninstall if needed
 	pip uninstall -y msspec
@@ -182,6 +186,17 @@ check_dependencies () {
 	test "$py_ver_minor" -ge "$py_ver_minor_min" || return 1
 	log_message "Ok\n"
 
+	# we need wxPython.
+	log_message "Checking if wxPython is installed..."
+	python -c "import wx"
+	if test "$?" -ne 0; then
+		log_message "You need wxPython to run MsSpec.\n"
+		log_message "Please look at informations at https://wxpython.org/pages/downloads/.\n"
+		return 1
+	else
+		log_message "Ok\n"
+	fi
+
 	# we need virtualenv
 	#log_message "Checking if virtualenv is installed..."
 	#command -V virtualenv || return 1