Added base File IO module

File IO module added - this will abstract File IO eventually.
squash support

Added some code to check before writing histfile - and to squash if
asked to do so. If no squash, then creates a new name for output by
appending current datetime to histfile name.
Removed unused imports
Check_space now works on multiple input files

Modified check_space() to check disk space based on an estimate from sum
of file sizes from multiple input files.
Added disk space check

Added code to check for diskspace before output
Input file check

Added code to check for existence and non-emptiness of input files
FileApi logic changed

FileApi now checks file status and takes appropriate action by itself
instead of returning a status
fileApi.check_space() logic change

check_space() now displays error and exits instead of returning the
value of free space needed
Input file(s) existence check + disk space check

Added code to check for existence of input file(s) and also check for
disk space based on sum(input_file_sizes)
Moved and renamed fileapi

Moved fileapi.py from sandbox/ to khmer/ and renamed it to file_api.py
Update file_api usage

import and usage of file_api have been updated in all scripts under
scripts/
argparse support added to first file

argparse support added to abund-ablate-reads.py
configure landscape.io service
cleanup version helper script
Add landscape.io Python code health badge
update project badges to include wheel, license
Pylint run

A few errors shown by pylint addressed
Few bug fixes + improvements to file-api

a. Updated check_space docstring
b. Added check_space overload to work with hashSizes
c. Modified check_space statvfs logic to address potential bug from here
(http://stackoverflow.com/questions/51658/cross-platform-space-remaining-on-volume-using-python#comment10259338_2372171)
Overload changed to new method, space check implemented in one script

file-api's check_space for hash tables is no longer an overload.
abundance-dist-single now checks diskspace before hashtable creation.
Disk space checked before hashtable.save() calls