check the .lua scripts for syntax error

.travis.yml

@@ -14,6 +14,7 @@ cache:
 addons:
   apt:
     packages:
+    - lua5.1
     - nsis
     - nsis-common
     - dpkg
@@ -31,6 +32,7 @@ script:
  - travis_retry make all-dependencies
  - make all
  - make check
+ - make check-scripts
  - make test
 
 # Automatically update the trait documentation and Lua API

Makefile

@@ -170,6 +170,12 @@ mod_ts_LIBS = $(COMMON_LIBS) $(STD_MOD_LIBS) $(mod_common_TARGET)
 PROGRAMS += mod_ts
 mod_ts: $(mod_ts_TARGET)
 
+check-scripts:
+	@echo
+	@echo "Checking for Lua syntax errors..."
+	@luac -p $(shell find mods/*/maps/* -iname '*.lua')
+	@luac -p $(shell find lua/* -iname '*.lua')
+
 check: utility mods
 	@echo
 	@echo "Checking for code style violations in OpenRA.Game..."