adding in ability to retrieve priorties list from Jira API

Change-Id: I35b7dcad0085e8cadf98afe46846e723d135cc56
Allow upload of attachments to Jira via CurlClient
Remove old code that was used to upload files
add ability to retreive statuses from Jira
Merge pull request #5 from okmpoki/master

New methods / Small fixes
Merge pull request #4 from addersuk/master

Add ability to return priorties from Jira
Added composer support
PHPClient - Add support for anonymous users
Fix authorship on new file
Merge pull request #7 from totten/anonymous

PHPClient - Add support for anonymous users
Merge pull request #6 from lightglitch/master

Added composer support
Improved functionality

Added getAttachment(), getProjects(), getProject(), getRoles(),
getRoleDetails() and downloadAttachment().
adjust style
Fix example in readme
Merge pull request #9 from coodix/master

Fix example in readme