microservice: Fix get annotations format

- Only split at the first occurence of '=', this allow values containing
  '=' character.
- Strip splitted parts, so we can have following forms:
  `key = value`, or `key= value `
- Also fix wrong index access annotation value, [1:-1] slices the content
  from 1 to second last, which leads to incompleted values.

python/seldon_core/microservice.py

@@ -101,11 +101,10 @@ def load_annotations() -> Dict:
             with open(ANNOTATIONS_FILE, "r") as ins:
                 for line in ins:
                     line = line.rstrip()
-                    parts = line.split("=")
+                    parts = list(map(str.strip, line.split("=", 1)))
                     if len(parts) == 2:
-                        value = parts[1][1:-1]
-                        logger.info("Found annotation %s:%s ", parts[0], value)
-                        annotations[parts[0]] = value
+                        logger.info("Found annotation %s:%s ", parts[0], parts[1])
+                        annotations[parts[0]] = parts[1]
                     else:
                         logger.info("bad annotation [%s]", line)
     except: