Issue 8: Remove asm from httpbuilder dependency
Issue 7: Move all credential gathering to before tasks
Upping version to 0.3.0
Issue 4: Add ability to print job xml
Issue 6: Add support for retiring jobs
Applying base plugin with jenkins plugin
Issue 6: Add support for retiring jobs
Merge branch 'v0.3.0'
  * Issue 4: Add ability to dump job xml
  * Issue 6: Add support for retiring jobs
  * Issue 7: Move server credential prompting to beginning of task
  * Issue 8: Remove asm dependency from http-builder