escape forward slashes

Author: mr-c

Jenkinsfile

@@ -12,7 +12,7 @@ pipeline {
           pybat(script: 'pip install .', returnStdout: true)
           pybat '''
 set BOOT2DOCKER_VM=default
-set PATH=%PATH%;"C:\Program Files\Docker Toolbox\"
+set PATH=%PATH%;"C:\\Program Files\\Docker Toolbox\\"
 docker-machine start %BOOT2DOCKER_VM%
 REM Set the environment variables to use docker-machine and docker commands
 @FOR /f "tokens=*" %i IN ('docker-machine env --shell cmd %BOOT2DOCKER_VM%') DO @%i