Python3.7 support and SDLC improvements

• Added steps to fdlc demo to show sensitive and invalid processor testing and behavior during deployment
• Added list_sensitive_processors and list_invalid_processors to nipyapi.canvas
• Added simple caching capability for certain calls to nipyapi.config
• Added placeholder tests for new functionality against next refactoring and integration run
• Missing assertion test in get_process_group_status
• deprecated use of tests_require setup.py as current best-practice
• Update ruamel.yaml to support Python 3.7 with passing tests
• Added test for docker image already present to avoid excessive downloading
• Added option to recurse from a given pg_id, rather than always from root, to several canvas functions
• Added default verify_ssl and ssl error squashing to config for user convenience
• Added filter option to specify whether exact or greedy matching should be used, still greedy by default
• Added hard logout when changing endpoint to ensure tokens are refreshed
• Updated tests
• updating travis to build all branches
• Fix travis for Python 3.7 testing support
• Fix edge case in delete process group where templates stop the revision from being refreshed
• Fixed test case to decode string correctly in old python versions
• Fixed race condition in test where not all processors started before test executes
• bugfix for missing status value in Processor DTO
• Updating pylint to ignore import errors on standard packages
• added logging to docker image control
• Bump version: 0.10.3 → 0.11.0
• Install requirements reset