Allow expression in arguments in CalibrationDefinition (#11)

* Allow expression in arguments in CalibrationDefinition

* Increment the version to 0.4.1

Author: aspcompiler

source/openpulse/.gitignore

@@ -1,5 +1,6 @@
 antlr/
 build/
 dist/
+_antlr/
 
 docs/_build

source/openpulse/openpulse/__init__.py

@@ -14,7 +14,7 @@
 the :obj:`~parser.parse` function.
 """
 
-__version__ = "0.4.0"
+__version__ = "0.4.1"
 
 from . import ast
 from . import parser

source/openpulse/openpulse/ast.py

@@ -90,7 +90,7 @@ class CalibrationDefinition(Statement):
     """
 
     name: Identifier
-    arguments: List[ClassicalArgument]
+    arguments: List[Union[ClassicalArgument, Expression]]
     qubits: List[Identifier]
     return_type: Optional[ClassicalType]
     body: List[Statement]