Add npm, maven, conan configs (excluding cache)

dot_conan/hooks/executable_attribute_checker.py

@@ -0,0 +1,8 @@
+
+def pre_export(output, conanfile, conanfile_path, reference, **kwargs):
+    # Check basic meta-data
+    for field in ["url", "license", "description"]:
+        field_value = getattr(conanfile, field, None)
+        if not field_value:
+            output.warn("Conanfile doesn't have '%s'. It is recommended to add it as attribute"
+                        % field)