set signup url and rename parameter to match with api
Merge branch 'master' of https://github.com/dst-hackathon/socialradar-android

# By kaotangP (3) and others
# Via kaotangP (4) and others
* 'master' of https://github.com/dst-hackathon/socialradar-android:
  Add a logic to check if user is logged in.
  add camera icon
  Refactor code.
  Remove Login with Facebook account.
  Add a Landing Activity.
comment the image absolute path for mac