Add a test script to compile typings and test on travis (#2808)

tests/scripts/compile_typings.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+# ANSI colors
+BOLD_GREEN='\033[1;32m'
+BOLD_RED='\033[1;31m'
+ANSI_RESET='\033[0m'
+
+# Download TypeScript to obtain the compiler.
+echo "Downloading TypeScript"
+npm install typescript
+
+# Generate Blockly typings.
+echo "Generating Blockly typings"
+npm run typings
+
+# Use the TypeScript compiler to compile the generated typings.
+echo "Compiling typings"
+cd typings
+../node_modules/.bin/tsc blockly.d.ts
+
+
+if [ $? -eq 0 ]
+then
+  echo -e "${BOLD_GREEN}TypeScript typings compiled successfully.${ANSI_RESET}"
+  exit 0
+else
+  echo -e "${BOLD_RED}Failed to compile TypeScript typings.${ANSI_RESET}" >&2
+  exit 1
+fi