fixed files that missing from .gitignore
fixed .gitignore back
create proposal
add requirement version usecase diagram
Delete requirement.pdf
Create requirement.md
Add requirement, Use case specification
add picture to requirement
edit use case picture
edit some primary scenario step
add information for Activity Diagram
Edit Alternative Scenario
add M2:Design document
add class diagram
add VM's IP
add core direcroty
add travis config file
rename travis config file
remove travis.yml
edit travis config file