Add libicu for Ubuntu 14.04

Progress towards #16

make-linux

@@ -22,14 +22,20 @@ if [ ! -e ../../sqlite/sqlite3 ]; then
   make sqlite
 fi
 
-if [ "$(lsb_release -s -r)" == "16.04" ]; then
-  export ICU_VERSION=55.1
-elif [ "$(lsb_release -s -r)" == "18.04" ]; then
-  export ICU_VERSION=60.2
-else
+case "$(lsb_release -s -r)" in
+  14.04)
+    export ICU_VERSION=52.1
+    ;;
+  16.04)
+    export ICU_VERSION=55.1
+    ;;
+  18.04)
+    export ICU_VERSION=60.2
+    ;;
+  *)
   echo "unsure what libicu version to use" >&2
   exit 1
-fi
+esac
 
 export ICU_VERSION_U=${ICU_VERSION//./_}
 make "$@"