Try to fix syntax

.travis.yml

@@ -34,5 +34,6 @@ before_script:
 
 script:
   # - xargo build --verbose --target $TARGET --no-default-features 
-  - xargo test --target thumbv7m-linux-eabi.json --no-run
+  - xargo --print target-list
+  - xargo test --target thumbv7m-linux-eabi --no-run
   - qemu-arm target/thumbv7m-linux-eabi/debug/mos6502

thumbv7m-linux-eabi.json

@@ -18,10 +18,14 @@
   "max-atomic-width": 32,
   "os": "linux",
   "panic-strategy": "abort",
-  "pre-link-args": ["-nostartfiles"],
+  "pre-link-args": {
+    "gcc": [
+      "-nostartfiles"
+    ]
+  },
   "relocation-model": "static",
   "target-c-int-width": "32",
   "target-endian": "little",
   "target-pointer-width": "32",
   "vendor": ""
-}
+}