Enable bundler caching in travis
check if asm maxgrade exists
Merge pull request #245 from wangqiang1208/bugfixing/achievement-nil-asm-maxgrade

Fix assessment max grade nil bug
Bugfix for html editor
Fix aesthetics after being hound-ed
change first to limit in survey controller, thus it will not reulst in an array
Merge pull request #247 from wangqiang1208/bugfixing/survey-summary-answer-order

Fix undefined method `order'  in surveys
Merge pull request #246 from kxmbrian/html_editor_fix

Bugfix for html editor
disable image button when there is no imageuploader
remove html_editor partial
Merge pull request #248 from wangqiang1208/bugfixing/disable-iamge-achievement-html-editor

Disable image button in achievement html editor
Merge pull request #244 from jsyeo/jsyeo-travis-cache

Enable bundler caching in travis
change can_start policy, if a student has ever started, let him start
refine code
Merge pull request #249 from wangqiang1208/features/mission-attempt-auth

if a student has ever started, let him start
enable dependent_on to be set across assessments (missions and trainings)
forms to show dependencies for assessments, ordered based on assessment type (mission or trainings)
small fix to include 'mission' or 'training' before dependent assessment
refactored can_start? to make available methods for finding dependent_assessment
updated access denied page to show uncompleted dependent assessment