Add user-generated annotations tests to the server (#1164)

* Add user-generated annotations tests to the server

Partially completes https://github.com/chanzuckerberg/cellxgene/issues/969

* Auto-format python code

* @skip_if: passing lambdas > than property strings

* Respond to feedback from @bkmartinjr

server/common/errors.py

@@ -2,6 +2,7 @@ class FilterError(Exception):
     """
     Raised when filter is malformed
     """
+
     pass
 
 
@@ -9,6 +10,7 @@ class JSONEncodingValueError(Exception):
     """
     Raised when data cannot be encoded into json
     """
+
     pass
 
 
@@ -16,6 +18,7 @@ class MimeTypeError(Exception):
     """
     Raised when incompatible MIME type selected
     """
+
     pass
 
 
@@ -23,6 +26,7 @@ class PrepareError(Exception):
     """
     Raised when data is misprepared
     """
+
     pass
 
 
@@ -30,6 +34,7 @@ class DatasetAccessError(Exception):
     """
     Raised when file loaded into a DataAdaptor is misformatted
     """
+
     pass
 
 
@@ -37,6 +42,7 @@ class DisabledFeatureError(Exception):
     """
     Raised when an attempt to use a disabled feature occurs
     """
+
     pass
 
 
@@ -44,6 +50,7 @@ class AnnotationsError(Exception):
     """
     Raised when an attempt to use the annotations feature fails
     """
+
     pass
 
 
@@ -51,4 +58,5 @@ class OntologyLoadFailure(Exception):
     """
     Raised when reading the ontology file fails
     """
+
     pass