Merge pull request #1 from jayschwa/patch-1

Fix `KeyError` when `TERM_PROGRAM` is undefined

ansiescapes.py

@@ -3,7 +3,7 @@
 import os
 
 ESC = '\u001B['
-isTerminalApp = 1 if os.environ['TERM_PROGRAM'] == 'Apple_Terminal' else 0
+isTerminalApp = os.environ.get('TERM_PROGRAM') == 'Apple_Terminal'
 
 def _(s): return s.decode('unicode_escape');