MAINT: Rename restrictions.py to asset_restrictions.py

For clarity as to what sort of restrictions these are

tests/finance/test_slippage.py

@@ -29,7 +29,7 @@ from zipline.finance.slippage import VolumeShareSlippage
 
 from zipline.protocol import DATASOURCE_TYPE, BarData
 from zipline.finance.blotter import Order
-from zipline.finance.restrictions import NoRestrictions
+from zipline.finance.asset_restrictions import NoRestrictions
 from zipline.data.data_portal import DataPortal
 from zipline.testing import tmp_bcolz_equity_minute_bar_reader
 from zipline.testing.fixtures import (

tests/test_algorithm.py

@@ -76,7 +76,7 @@ from zipline.finance.commission import PerShare
 from zipline.finance.execution import LimitOrder
 from zipline.finance.order import ORDER_STATUS
 from zipline.finance.trading import SimulationParameters
-from zipline.finance.restrictions import (
+from zipline.finance.asset_restrictions import (
     Restriction,
     HistoricalRestrictions,
     StaticRestrictions,

tests/test_bar_data.py

@@ -23,7 +23,7 @@ import pandas as pd
 
 from zipline._protocol import handle_non_market_minutes
 
-from zipline.finance.restrictions import (
+from zipline.finance.asset_restrictions import (
     Restriction,
     HistoricalRestrictions,
     RESTRICTION_STATES,

tests/test_finance.py

@@ -37,7 +37,7 @@ from zipline.data.minute_bars import BcolzMinuteBarReader
 from zipline.data.data_portal import DataPortal
 from zipline.data.us_equity_pricing import BcolzDailyBarWriter
 from zipline.finance.slippage import FixedSlippage
-from zipline.finance.restrictions import NoRestrictions
+from zipline.finance.asset_restrictions import NoRestrictions
 from zipline.protocol import BarData
 from zipline.testing import (
     tmp_trading_env,

tests/test_history.py

@@ -28,7 +28,7 @@ from zipline.errors import (
     HistoryWindowStartsBeforeData,
 )
 from zipline.finance.trading import SimulationParameters
-from zipline.finance.restrictions import NoRestrictions
+from zipline.finance.asset_restrictions import NoRestrictions
 from zipline.testing import (
     create_minute_df_for_asset,
     str_to_seconds,

tests/test_restrictions.py

@@ -5,7 +5,7 @@ from functools import partial
 
 from toolz import groupby
 
-from zipline.finance.restrictions import (
+from zipline.finance.asset_restrictions import (
     RESTRICTION_STATES,
     Restriction,
     HistoricalRestrictions,

tests/test_tradesimulation.py

@@ -24,7 +24,7 @@ from zipline import TradingAlgorithm
 from zipline.gens.sim_engine import BEFORE_TRADING_START_BAR
 
 from zipline.finance.performance import PerformanceTracker
-from zipline.finance.restrictions import NoRestrictions
+from zipline.finance.asset_restrictions import NoRestrictions
 from zipline.gens.tradesimulation import AlgorithmSimulator
 from zipline.sources.benchmark_source import BenchmarkSource
 from zipline.test_algorithms import NoopAlgorithm