v3.3.0

Changes:

• Cassandra DB driver improvements
  • Can now create an instance of the driver using an existing DB instance thanks to @mixedCase and @kenjones-cisco (#30 and #32)
• Timestamp format can be customized in CLI thanks to @bobmeister (#17)
• Github migration sources parse URL fragments thanks to @thurt (#22)
• CLI available via docker thanks to @Its-Alex (#24 and #27)
• Use keyed struct fields for file sources to fix GAE issues thanks to @wmetaw (#43)
• dep used to manage dependencies
• Fix postgres driver locking thanks to @Teddy-Schmitz (#13)
• Loaded source and db drivers displayed in CLI help text
• Actually support S3, go-bindata, and GCS migration sources in the CLI. Fixes #52
• Support godoc vfs sources thanks to @SamWhited
• Build binaries with statically linked libraries. Fixes #45
• Improve usability of the create command by making the -ext flag required (#53 (comment))
  • This is not considered a backwards incompatible change as any migration created without an extension would have erred during loading