Simplify CocoaPods linting

Closes #1066

Author: jberkel

Tests/CocoaPods/.gitignore

@@ -7,9 +7,13 @@ if [ -n "$BUILD_SCHEME" ]; then
         make test BUILD_SCHEME="$BUILD_SCHEME"
     fi
 elif [ -n "$VALIDATOR_SUBSPEC" ]; then
-    cd Tests/CocoaPods && make test
+    if [ "$VALIDATOR_SUBSPEC" == "none" ]; then
+      pod lib lint --no-subspecs
+    else
+      pod lib lint --subspec="${VALIDATOR_SUBSPEC}"
+    fi
 elif [ -n "$CARTHAGE_PLATFORM" ]; then
     cd Tests/Carthage && make test CARTHAGE_PLATFORM="$CARTHAGE_PLATFORM"
 elif [ -n "${PACKAGE_MANAGER_COMMAND}" ]; then
-    swift ${PACKAGE_MANAGER_COMMAND}
+    swift "${PACKAGE_MANAGER_COMMAND}"
 fi