Fixed KiCost variants: when setting a field hat doesn't exist

Fixes #105

CHANGELOG.md

@@ -42,6 +42,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   (INTI-CMNB/kibot_variants_arduprog#4)
 - Makefile: %VALUE not expanded in the directory targets.
 - KiCost variants: empty DNF fields shouldn't be excluded. (#101)
+- KiCost variants: problems when setting a field in a variant that doesn't
+  exist when no variant is selected. (#105)
 
 
 ## [0.11.0] - 2021-04-25

kibot/kicad/v5_sch.py

@@ -726,6 +726,15 @@ class SchematicField(object):
 
     def __init__(self):
         super().__init__()
+        self.horizontal = True  # H -> True, V -> False
+        self.x = 0
+        self.y = 0
+        self.size = 50
+        self.flags = '0001'
+        self.hjustify = 'C'
+        self.vjustify = 'C'
+        self.italic = 'N'
+        self.bold = 'N'
 
     @staticmethod
     def parse(line, f):