Don't capitalize delorean in requirements.txt
created a new generator-backed trading environment for testing.
other details:
    - also fixed grammatical errors in loader's status messages.
    - converting the treasury curves to an ordered dict.
    - moved to using a lambda for clarity as per @ehebert
    - initializing calendar end dates to be midnight of current date in
    - US/Eastern. Yahoo data isn't available until midnight eastern.
Merge pull request #90 from quantopian/fake_environment

Fake environment
trying to fix broken jenkins build that seems to be due to the end time
of the trading calendar calculations and availability of data from yhoo.
changing the calendar test for lse to use the last available date
rather than the end date.
Merge pull request #91 from quantopian/calendar_fix

changing the calendar test for lse to use the last available date
(confirmed this branch builds on jenkins before merging)
Fixes crashes when using numpy log on a batch transform data panel.

The recent change to the creation of the data panel ended up with
a panel with the dtype of 'object', which was causing numpy ufuncs
like `log` to crash out on an `AttributeError`.

This forces all frames in the panel to use a dtype of 'float',
we may want to look at seeting a dtype on a frame by frame basis,
e.g. 'volume' may more accurately be 'int'.
added a decorator for applying an environment to a function context.
added functools.wraps as per @richafrank
Merge pull request #92 from quantopian/noop_env_fix_1470

added a decorator for applying an environment to a function context.
tradingcalendar was assuming eastern time when calculating its end date,
switched to use UTC and utcnow. Also factored the common code out of
the nyse and lse specific tests into a helper method.
Upgrade msgpack-python to 0.3.0
Fix flake8 error
Disable test_{,lse_}calendar_vs_environment until issue #93 is addressed

These two tests are nonessential and the test failures reflect bugs in
the tests, not bugs in the code.
Fix flake8 problem
Prevents entire data panel being collapsed when a stock stops trading.

The call to `Panel.dropna` after the fillna was deleting all values,
if a stock stopped trading mid run and thus provided volume 0.

i.e. if any sid had 0 non-null values the entire panel of frames
would be truncated.

It's possible to avoid the collapse via by adding the `how='all'` flag
to `dropna`, however with the current tick based creation of the panel,
the `dropna` with `how='all'` should be functionally equivalent to
not dropping at all.

The dropna has been dropped in favor of leaving the drop to algorithm
code.