More cleanup and minor improvements

• improve prompt patterns
• add ssh config file example
• examples clean up
• lots of readme changes/improvements
• lots of docstring clean up
• channel now has send_input and send_inputs for singular or plural inputs respectively
• improve unit testing a bit -- more fixtures, try to cover more possible cases
• NetworkDriver is an ABC as it should be now
• few random little bug fixes
• update dev requirement pinned versions
• regen docs

Internal improvements, API changes to get closer to "stable"

• improve docs hopefully everywhere basically
• minor improvements to channel reading
• added message to timeout decorator to be more clear why/where things time out
• migrated away from signals (yay for windows i guess) for decorator -- due to systemssh doing things in new procs signal wouldn't work there, new implementation is concurrent futures threads
• added timeout_exit to kill connections if timeout occurs (or not)
• a little bit better/more logging especially in decorator (more to go for sure though)
• updated all core drivers to reflect on_open/on_close callabales, removed "exit_command" entirely
• simplified network driver due to moving to on_open/on_close
• modified netowrk driver send_commands to only accept a list of commands to send, added send_command which only accepts a single command
• due to above change only return a list of responses if using send_commands -- if using send_command just return a response object
• added exception for keepalive failure -- raised by keepalive thread if/when keepalives are missed for > 3x the keepalive interval -- this may need to get changed/tweaked in the future and/or add a keepalive_exit flag like the timeout
• textfsm_parse_output no longer updates the response object w/ results (in place operation), it now returns results and there is no "structured_result" attribute of the response object
• removed external function validation stuff from helper -- was neat maybe but not necessary for now, on_open/on_close simply accept callables no need to parse a text string to try to import things... could be added back in the future easy enough if it seems useful
• transport base class now has a useful init method that sub classes can super
• transport child classes that create a socket (paramiko/ssh2) now do so via composition instead of inheritance -- mro was just annoying, plus couldnt (easily? at all?) super w/ different args to transport vs socket (didnt look hard, composition seems fine)
• systemssh/telnet transport store channel args needed for authenticaiton (prompt pattern/ansi/return char) as private args now. they are used for initial auth then ignored...
• systemssh ssh args/open cmd improvements
• add keepalive for systemssh/telnet (network only)
• systemssh/telnet store _timeout_ops (channel timeout basically) as a private arg for same reasons as the auth stuff -- timeout authentication things, this is ignored after auth occurs
• systemssh improved pty authentication handling
• driver/driver (scrape) now doesnt store most arguments passed to it in the object itself -- they are instead stored in _initialization_args and passed to the channel and transport as needed
• way way way better repr for scrape
• significantly better netmiko compatability setup

Transport Keepalives, General Improvements

readme updates
add "smoke tests" -- basic helpful scripts i use when making changes
remove unused blocking method from transport
improve auth handling for system ssh
move some things from scrape -> networkdriver where they make more sense
add transport keepalive support
regen docs

SSH Strict Key Checking

Add strict key checking to Paramiko and ssh2-python transport
Add ssh known hosts handling
Example updates/cleanup
Readme updates/cleanup

SSH Config Support Enhancement

• Readme updates
• Rename containers
• Fix telnet and System ssh login timeouts
• Type/cleanup docstrings for SSH parsing
• SSH config file support for ssh2 and system

Scrapli!

-rename -> scrapli
-add test telnet support
-support 3.6+ again (named tuple instead of data class)
-rename result->response and reswizzle
-drop TextFSM off of send command, is available via response object
-regen docs
-remove flush as it seemed useless...
-cleanup docstrings (remove noqa stuff)

Feature adds

Generated docs
Added Netmiko compatibility
Improved/added testing (still needs to be redone a bit to make it easier, but progress!)
Added platform drivers (untested other than IOSXE at this point, but as it is mostly a rip from ssh2net it should be solid)
Add to Makefile
Added docker-compose
Dropped py36 to get data classes to use for the privilege levels
Minor API adds (send_interactive in network driver)

Initial release!

2019.02.01

mypy to requirements-dev