Fix a small ImapClient bug
Fix a small ImapClient bug

Summary: I found a small bug in ImapClient which makes it crash when making a SEARCH using MODSEQ. The bug will be fixed in 0.12. In the meantime, I changed requirements.txt to point to our ImapClient fork.

Test Plan: Ran a full sync and an update afterwards.

Reviewers: emfree, spang

Reviewed By: spang

Differential Revision: https://review.inboxapp.com/D315

EthanBlackburn/sync-engine,closeio/nylas,ErinCall/sync-engine,jobscore/sync-engine,closeio/nylas,Eagles2F/sync-engine,PriviPK/privipk-sync-engine,closeio/nylas,Eagles2F/sync-engine,PriviPK/privipk-sync-engine,nylas/sync-engine,EthanBlackburn/sync-engine,PriviPK/privipk-sync-engine,jobscore/sync-engine,Eagles2F/sync-engine,gale320/sync-engine,PriviPK/privipk-sync-engine,nylas/sync-engine,wakermahmud/sync-engine,wakermahmud/sync-engine,PriviPK/privipk-sync-engine,gale320/sync-engine,ErinCall/sync-engine,gale320/sync-engine,gale320/sync-engine,EthanBlackburn/sync-engine,closeio/nylas,jobscore/sync-engine,wakermahmud/sync-engine,ErinCall/sync-engine,nylas/sync-engine,jobscore/sync-engine,Eagles2F/sync-engine,ErinCall/sync-engine,EthanBlackburn/sync-engine,EthanBlackburn/sync-engine,gale320/sync-engine,ErinCall/sync-engine,wakermahmud/sync-engine,Eagles2F/sync-engine,nylas/sync-engine,wakermahmud/sync-engine