MAINT: Removed unused test_utils.check functions.

The test_utils were the only references to the blist package,
removing so that blist can be removed as a dependency.
ENH: Add len() functionality to BarData.
DOC: Added doc string for instant_fill.
TST: Defend against non-trading days as period start in commission test.

A bug in the create_random_simulation_parameters allows the period
start to be a non-trading day.

That bug was causing the commission tests to randomly fail, e.g.
when the period start was on Good Friday, because the commission was
created on hour three of Good Friday, instead of the next Monday.
When it hit that case, the test commission is never processed.

Defend against that bug by using the first open of the simulation
parameters which is more guaranteed to be during market hours,
when creating the test commission.

This is in place of fixing the bug in the random parameters function
or making the parameters non-random, which are other potential fixes.
BLD: Add LD_LIBRARY_PATH to fix Travis CI failures.
REF: Moved trading-related methods from AlgoProxy.
BUG: Make all iteration related methods fo BarData match __iter__

`for s in data` and methods like `for s in data.keys` were not producing
the same list of active sids

Make the other iteration methods match __iter__ by using the contains
method to check whether or not the sid is active.

For use of data outside of the algoscript context, which needs access
to all data fields use data._data
BUG: Make BarData iterkeys method match dict iterkeys behavior.

Use a generator, instead of creating a list.
PERF: Speed up get_open_and_closes by assigning entire columns

to DataFrame, instead of row by row
MAINT: Removed unused parameter
MAINT: Initialize Portfolio object with default values for attributes

instead of no attributes at all
ENH: Add calendar and test for Toronto stock exchange.

Note that the calendar test is decorated with @nottest (as per the other calendar test functions).  I've run the test to confirm the calendar works.  The differences between the env (Yahoo Finance of GSPTSE) and the calendar are illustrated in the tradingcalendar_tse file and are confirmed to be errors on Yahoo Finance's part.
ENH: Added functionality to download Canadian treasury curves.

Added automatic switching of treasury curves based on index sent to environment.
MAINT: Update URL for free benchmark data.

Keep pace with Yahoo!'s change from ichart.yahoo.com to
ichart.finance.yahoo.com
MAINT: print function clean up in preparation for Python 3

- Use `print()` function for all print calls
- Fix strip and format calls that were on the outside of the
  print function for some reason.
  (Which were breaking in Python 3 because of print returning None.)
- Remove commented out print calls.
MAINT: Updated libraries

iso8601, pytz, numpy, python-dateutil, six, Cython, requests,

nose-parameterized, nose-ignore-docstring, scipy, matplotlib,
patsy

Note that patsy must install before statsmodels.
MAINT: Use six for Python 3 compatible names and behavior.

Use the six module to import functions and types that are
consistent between Python 2 and 3, so that one code base can
support both versions.

- Use integer types instead of int and long.
- Use string_types instead of basestring.
- Account for iteritems, itervalues, iterkeys.
- Use six.moves for filter and zip, reduce
- Use compatible bytes for md5 hasher.
- xrange and range
MAINT: Use explicit relative pathing for Python 3 compatibility.

Python 3 requires submodules to have more explicit pathing, so use
the dot syntax to declare submodules which are in the same directory
as another module.
MAINT: Make answer key reading compatible with Python 3.

Ensure reading of bytes and checking against byte type, when
parsing the Excel spreadsheet which contains the answers.
MAINT: Explicitly convert map to list when converting answer key values.

For compatibility with iterator version of map in Python 3.

Also always use iterator version of map,
so that code path is exercised in Python 2.