Sketch support (#879)

Squashed commit of many changes, see PR #879 for full details.

Author: adam-urbanczyk

azure-pipelines.yml

@@ -14,29 +14,7 @@ resources:
       name: CadQuery/conda-packages
       endpoint: CadQuery
 
-jobs:
-- template: conda-build.yml@templates
-  parameters:
-    name: Linux_37
-    vmImage: 'ubuntu-18.04'
-    py_maj: 3
-    py_min: 7
-
-- template: conda-build.yml@templates
-  parameters:
-    name: macOS_37
-    vmImage: 'macOS-10.15'
-    py_maj: 3
-    py_min: 7
-
-- template: conda-build.yml@templates
-  parameters:
-    name: Windows_37
-    vmImage: 'vs2017-win2016'
-    py_maj: 3
-    py_min: 7
-    conda_bld: 3.18
-    
+jobs:  
 - template: conda-build.yml@templates
   parameters:
     name: Linux_38

cadquery/__init__.py

@@ -27,6 +27,7 @@
     StringSyntaxSelector,
     Selector,
 )
+from .sketch import Sketch
 from .cq import CQ, Workplane
 from .assembly import Assembly, Color, Constraint
 from . import selectors
@@ -66,6 +67,7 @@
     "StringSyntaxSelector",
     "Selector",
     "plugins",
+    "Sketch",
 ]
 
 __version__ = "2.1"