trial and custom command and fs method support

Merging completed WIP and updates into release (#6)
Notes

Changes to batchtk —

Global CONSTANTS moved to batchtk.header
— check header.py re: parsing of environment variables and aliases
— change to certain CONSTANTS to resolve naming ambiguities

inspyredtk
— WIP module (no current implementation) utilizing inspyred population based algos

raytk
— trial function that supports interfacing with ray tune/train now utilizing runtk.trial function

runtk
— dispatchers now support custom filesystem and command classes (see protocol classes in batchtk.utils)
— header now moved to its own submodule to avoid circular imports
— runners.py now supports (toggling) singleton, see `_` attributes below Runner class. A Runner will be singleton by default, can do:
```
Runner_Constructor = get_class()
Runner_Constructor._reinstance = True
```
to ensure non-singleton, reinstantiation
— sockets.py
internal refactoring
— submits with new attributes: 
```
script_args -> set of {arguments,} that the script takes
script_template -> the template of the script that will be written to .sh
submit_template -> the submit command (i.e. submission through some scheduling system)
handles -> any handles for communication (depends on filesystem or socket based communication,,,)
```
—trial
containing function which runs a single trial with the—
```
start()
connect()
recv()
clean()
```
invocations

— util_class containing:
RunConfig and Comm classes which segregate the trial configuration and trial communication methods

sshtk
—WIP module supporting file transfer via fabric & paramiko

utils
—now containing FS and CMD protocol classes and implementations for local and remote job submission.

for c/w other projects, (i.e. NetPyNE)

• update release number