Add exceptions

src/exceptions.py

@@ -0,0 +1,14 @@
+class UOWSError(Exception):
+    """Problem authenticating with the user office web service"""
+
+
+class ProposalAllocationsError(Exception):
+    """Problem connecting with the proposal allocations api"""
+
+
+class BadCredentialsError(Exception):
+    """ "Bad Credentials Provided"""
+
+
+class BadJWTError(Exception):
+    """Raised when a bad jwt has been given to the service"""