Delete query_pattern from ConceptMap (#147)

## What is the goal of this PR?

Delete query_pattern from ConceptMap

Author: Alex Walker

grakn/concept/answer/concept_map.py

@@ -31,12 +31,8 @@ class ConceptMap(Answer):
 
     _THING = "thing"
 
-    def __init__(self, mapping: Mapping[str, Concept], query_pattern: str):
+    def __init__(self, mapping: Mapping[str, Concept]):
         self._map = mapping
-        self._query_pattern = query_pattern
-
-    def query_pattern(self):
-        return self._query_pattern
 
     def map(self):
         return self._map
@@ -73,5 +69,4 @@ def _of(concept_map_proto: answer_proto.ConceptMap):
         else:
             concept = concept_proto_reader.type_(res_concept.type)
         variable_map[res_var] = concept
-    query_pattern = None if concept_map_proto.pattern == "" else concept_map_proto.pattern
-    return ConceptMap(variable_map, query_pattern)
+    return ConceptMap(variable_map)

grakn/concept/type/attribute_type.py

@@ -265,6 +265,20 @@ def put(self, value: str):
     def get(self, value: str):
         return self._get_internal(concept_proto_builder.string_attribute_value(value))
 
+    def get_regex(self):
+        method = concept_proto.Type.Req()
+        get_regex_req = concept_proto.AttributeType.GetRegex.Req()
+        method.attribute_type_get_regex_req.CopyFrom(get_regex_req)
+        regex = self._execute(method).attribute_type_get_regex_res.regex
+        return None if len(regex) == 0 else regex
+
+    def set_regex(self, regex: str):
+        method = concept_proto.Type.Req()
+        set_regex_req = concept_proto.AttributeType.SetRegex.Req()
+        set_regex_req.regex = regex
+        method.attribute_type_set_regex_req.CopyFrom(set_regex_req)
+        self._execute(method)
+
     def is_string(self):
         return True