sysutils/py-plumbum: update to 1.6.0

Port Changes:

• Add test target using nosetests.
• Switch to GH distribution to get unit tests.
• Add pkg-plist (do not use autoplist generation)

Change Log:

• Added support for Python 3.5, PyPy, and better Windows and Mac support, with CI testing (#218, #217, #226)
• Colors: Added colors module, support for colors added to cli (#213)
• Machines: Added .get() method for checking several commands. (#205)
• Machines: local.cwd now is the current directory even if you change the directory with non-Plumbum methods (fixes unexpected behavior). (#207)
• SSHMachine: Better error message for SSH (#211)
• SSHMachine: Support for FreeBSD remote (#220)
• Paths: Now a subclass of str, can be opened directly (#228)
• Paths: Improved pathlib compatibility with several additions and renames (#223)
• Paths: Added globbing multiple patterns at once (#221)
• Commands: added NOHUP modifier (#221)
• CLI: added positional argument validation (#225)
• CLI: added envname, which allows you specify an environment variable for a SwitchAttr (#216)
• CLI terminal: addded Progress, a command line progress bar for iterators and ranges (#214)
• CLI: add invoke, which allows you to programmatically run applications (#149)
• CLI: add --help-all and various cosmetic fixes: (#125), (#126), (#127)
• CLI: add root_app property (#141)
• Machines: getattr now raises AttributeError instead of CommandNotFound (#135)
• Paramiko: keep_alive support (#186)
• Paramiko: does not support piping explicitly now (#160)
• Parmaiko: Added pure SFTP backend, gives STFP v4+ support (#188)
• Paths: bugfix to cwd interaction with Path (#142)
• Paths: read/write now accept an optional encoding parameter (#148)
• Paths: Suffix support similar to the Python 3.4 standard library pathlib (#198)
• Commands: renamed setenv to with_env (#143)
• Commands: pipelines will now fail with ProcessExecutionError if the source process fails (#145)
• Commands: added TF and RETCODE modifiers (#202)
• Experimental concurrent machine support in experimental/parallel.py
• Several minor bug fixes, including Windows and Python 3 fixes (#199, #195)