Add a script for running tests (intended for use by the Flutter customer tests repository) (#648)

See https://github.com/flutter/tests/blob/main/registry/flutter_reactive_ble.test

Author: jason-simmons

bin/flutter_customer_test.bat

@@ -0,0 +1,25 @@
+PUSHD packages\flutter_reactive_ble
+CALL flutter analyze --no-fatal-infos || GOTO :END
+CALL flutter test || GOTO :END
+POPD
+
+PUSHD packages\reactive_ble_mobile
+CALL flutter analyze --no-fatal-infos || GOTO :END
+CALL flutter test || GOTO :END
+POPD
+
+PUSHD packages\reactive_ble_platform_interface
+CALL flutter analyze --no-fatal-infos || GOTO :END
+CALL flutter test || GOTO :END
+POPD
+
+@ECHO.
+@ECHO.
+@ECHO Testing complete.
+GOTO :EOF
+
+:END
+@ECHO.
+@ECHO.
+@ECHO Testing failed.
+EXIT /B 1

bin/flutter_customer_test.sh

@@ -0,0 +1,5 @@
+set -e
+
+(cd packages/flutter_reactive_ble; flutter analyze --no-fatal-infos; flutter test)
+(cd packages/reactive_ble_mobile; flutter analyze --no-fatal-infos; flutter test)
+(cd packages/reactive_ble_platform_interface; flutter analyze --no-fatal-infos; flutter test)