Bloxberg proof of concept

Summary

This MR allow users to certify a single entity with the Bloxberg blockchain.

Tests are still missing.

Focus

• Does the API look usable for other programmers?

Test Environment

• Start your own CaosDB server and make sure that your pycaosdb.ini will connect to it.
• Install this project with pip3 install .
• Start Python shell and run:

import caosadvancedtools.bloxberg.bloxberg as blx
blx.demo_run()

• Check in your CaosDB instance that the RecordTypes and Records look OK: https://localhost:10443/Entity/?query=FIND%20Bloxb*
• Verify the certificate (stored at /tmp/cert.json or saved from the certificate Record) at https://certify.bloxberg.org/verify

Check List for the Author

• All automated tests pass
• Reference related Issue: #34 (closed)
• Up-to-date CHANGELOG.md
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there spezifications? Are they satisfied?

For further good practices have a look at our review guidelines.

src/caosadvancedtools/models/parser.py

 """
-This script provides the a function to read a DataModel from a yaml file.
+This module (and script) provides methods to read a DataModel from a YAML file.
 
 If a file name is passed to parse_model_from_yaml it is parsed and a DataModel
 is created. The yaml file needs to be structured in a certain way which will be
@@ -13,7 +13,7 @@ and will be added with the respective importance. These properties can be
 RecordTypes or Properties and can be defined right there.
 Every Property or RecordType only needs to be defined once anywhere. When it is
 not defined, simply the name can be supplied with no value.
-Parents can be provided under the inherit_from_xxxx keywords. The value needs
+Parents can be provided under the 'inherit_from_xxxx' keywords. The value needs
 to be a list with the names. Here, NO NEW entities can be defined.
 """
 import re
@@ -24,9 +24,10 @@ import yaml
 
 from .data_model import DataModel
 
+# Keywords which are allowed in data model descriptions.
 KEYWORDS = ["parent",
             "importance",
-            "datatype",
+            "datatype",  # for example TEXT, INTEGER or REFERENCE
             "unit",
             "description",
             "recommended_properties",
@@ -95,12 +96,12 @@ class Parser(object):
         Parameters
         ----------
         filename : str
-        The path to the YAML file.
+          The path to the YAML file.
 
         Returns
         -------
         out : DataModel
-        The created DataModel
+          The created DataModel
         """
         with open(filename, 'r') as outfile:
             ymlmodel = yaml.load(outfile, Loader=SafeLineLoader)
@@ -112,12 +113,12 @@ class Parser(object):
         Parameters
         ----------
         string : str
-        The YAML string.
+          The YAML string.
 
         Returns
         -------
         out : DataModel
-        The created DataModel
+          The created DataModel
         """
         ymlmodel = yaml.load(string, Loader=SafeLineLoader)
         return self._create_model_from_dict(ymlmodel)
@@ -128,12 +129,12 @@ class Parser(object):
         Parameters
         ----------
         ymlmodel : dict
-        The dictionary parsed from a YAML file.
+          The dictionary parsed from a YAML file.
 
         Returns
         -------
         out : DataModel
-        The created DataModel
+          The created DataModel
         """
 
         if not isinstance(ymlmodel, dict):
@@ -185,15 +186,15 @@ class Parser(object):
         Parameters
         ----------
         name :
-        The value to be converted to a string.
+          The value to be converted to a string.
 
         context : obj
-        Will be printed in the case of warnings.
+          Will be printed in the case of warnings.
 
         Returns
         -------
         out : str
-        If `name` was a string, return it. Else return str(`name`).
+          If `name` was a string, return it. Else return str(`name`).
         """
         if name is None:
             print("WARNING: Name of this context is None: {}".format(context),