added sentry logger
added tests
added raven-go to .travis.yml
Saving off entry string for use in panic

as the reader is not seekable and without this the panic string is
always empty :scream_cat:
Switching to io.MultiWriter for clarity
Adding tests for PanicLevel behavior, plus changing behavior!  :scream_cat:
various fixes
Making panic level assertions more helpful
Merge pull request #76 from meatballhat/save-entry-string-for-panic

Panic with entry instead of entry string
added delivery timeout
add GetLevel support

Signed-off-by: Doug Davis <dug@us.ibm.com>
readme: fix syslog example
Merge pull request #79 from duglin/AddGetLevel

add GetLevel support
syslog: let syslog output lookup level directly in Entry struct

Log level has moved from `entry.Data["level"]` to `entry.Level`. Use
that to get the right level.

Fix: #82
Merge pull request #84 from vincentbernat/fix/syslog

syslog: let syslog output lookup level directly in Entry struct
Fix Papertrail bug

Conflicts:
	hooks/papertrail/papertrail.go
timeout is now configurable and documented
Merge pull request #74 from gigaroby/sentry-hook

Added sentry hook
documentation fix
Merge pull request #85 from gigaroby/doc-fix

documentation fix