ISS: install missing dep

INSTALL.md

@@ -68,7 +68,8 @@ sudo apt install -yq predict \
                      socat \
                      php7.2-fpm \
                      php7.2-sqlite \
-                     sqlite3
+                     sqlite3 \
+                     libgfortran5
 ``` 
 
 ```

install.sh

@@ -62,7 +62,8 @@ sudo apt install -yq predict \
                      socat \
                      php7.2-fpm \
                      php7.2-sqlite \
-                     sqlite3
+                     sqlite3 \
+                     libgfortran5
 
 sudo pip3 install numpy ephem tweepy Pillow
 log_done "Packages installed"