Version 1.5.0

New functionality

• add_context & remove_all_context API
• Add data-max-chunk-size to input created by image_upload_tag
• Add moderation and phash parameters to explicit API

Other changes

• Modify Travis configuration to test NodeJS v4 and v6 only.
• Modify TEST_TAG
• Use Sinon spy in start_at test
• Support context as hash argument in context API
• Delete streaming profiles after tests
• Fix signing URL tests, Fixes #89
• Add timeout to delete streaming profile test
• add tests for add_context & remove_all_context
• add add_context & remove_all_context methods
• fix test description
• add test to phash in an explicit call
• add test to moderation parameter in an explicit call
• Add test to accepts {effect: art:incognito}
• support phash in explicit call
• Fix missing moderation parameter in an explicit call
• Fix nil to null. Call config() with parameter name.