checking to see if opt/mycroft/skills exists and is writable

scripts/install-msm.sh

@@ -1,8 +1,17 @@
 #!/usr/bin/env bash
+
+SKILLS_DIR='/opt/mycroft/skills'
 # exit on any error
 set -Ee
 rm -rf msm
 git clone https://github.com/MycroftAI/msm.git msm
 chmod +x msm/msm
-sudo mkdir -p /opt/mycroft/skills
-sudo chown $USER:$USER /opt/mycroft/skills
+
+if [ ! -d ${SKILLS_DIR} ]; then
+    sudo chown $USER:$USER ${SKILLS_DIR}
+fi
+
+if [ ! -w ${SKILLS_DIR} ]; then
+	sudo mkdir -p ${SKILLS_DIR}
+fi
+