Merge pull request #742 from package-url/update-must-to-shall

Update "must" to "shall" for ISO standard
Merging with single approval because this is an editorial correction to change the schema text to match changes to the proposed PURL Ecma Standard. The change from must to shall is to confirm with ISO terminology.
There were only 3 instances in each file.

Author: mjherzog

schemas/purl-type-definition.schema-1.0.json

@@ -31,13 +31,13 @@
       "properties": {
         "permitted_characters": {
           "title": "Permitted characters in this PURL component",
-          "description": "A regular expression (ECMA-262 dialect) defining the 'Permitted characters' for this component of this Package-URL type. If provided, this must be a subset of the 'Permitted characters' defined in the PURL specification.",
+          "description": "A regular expression (ECMA-262 dialect) defining the 'Permitted characters' for this component of this Package-URL type. If provided, this shall be a subset of the 'Permitted characters' defined in the PURL specification.",
           "type": "string",
           "format": "regex"
         },
         "case_sensitive": {
           "title": "Case sensitive",
-          "description": "true if this PURL component is case sensitive. If false, the canonical form must be lowercased.",
+          "description": "true if this PURL component is case sensitive. If false, the canonical form shall be lowercased.",
           "type": "boolean",
           "default": true
         },
@@ -141,7 +141,7 @@
     },
     "namespace_definition": {
       "title": "Namespace definition",
-      "description": "Definition of the namespace component for this PURL type. The PURL namespace component must be required, optional or prohibited for a specific PURL type definition.",
+      "description": "Definition of the namespace component for this PURL type. The PURL namespace component shall be required, optional or prohibited for a specific PURL type definition.",
       "type": "object",
       "required": [
         "requirement"

schemas/purl-type-definition.schema-1.1.json

@@ -31,13 +31,13 @@
       "properties": {
         "permitted_characters": {
           "title": "Permitted characters in this PURL component",
-          "description": "A regular expression (ECMA-262 dialect) defining the 'Permitted characters' for this component of this Package-URL type. If provided, this must be a subset of the 'Permitted characters' defined in the PURL specification.",
+          "description": "A regular expression (ECMA-262 dialect) defining the 'Permitted characters' for this component of this Package-URL type. If provided, this shall be a subset of the 'Permitted characters' defined in the PURL specification.",
           "type": "string",
           "format": "regex"
         },
         "case_sensitive": {
           "title": "Case sensitive",
-          "description": "true if this PURL component is case sensitive. If false, the canonical form must be lowercased.",
+          "description": "true if this PURL component is case sensitive. If false, the canonical form shall be lowercased.",
           "type": "boolean",
           "default": true
         },
@@ -141,7 +141,7 @@
     },
     "namespace_definition": {
       "title": "Namespace definition",
-      "description": "Definition of the namespace component for this PURL type. The PURL namespace component must be required, optional or prohibited for a specific PURL type definition.",
+      "description": "Definition of the namespace component for this PURL type. The PURL namespace component shall be required, optional or prohibited for a specific PURL type definition.",
       "type": "object",
       "required": [
         "requirement"