Merge pull request #231 from philipr-za/philip-204-check-commitment-transaction-fee

Check funder can afford commitment transaction fee when receiving update_fee

diff --cc src/ln/channel.rs
Simple merge

diff --cc src/ln/channelmanager.rs
index c5bf8b337ecf207bfa7d9c74cd4eb7b18f2f4574,0600c4e703cd82bdd3bb98a83f963f2e95817054..20a3779899a620b185723bdf78d7513017321ee4
--- 1/src/ln/channelmanager.rs
--- 2/src/ln/channelmanager.rs
+++ b/src/ln/channelmanager.rs
@@@ -3209,8 -3210,9 +3209,9 @@@ mod tests 
        use chain::chaininterface;
        use chain::transaction::OutPoint;
        use chain::chaininterface::{ChainListener, ChainWatchInterface};
 -      use chain::keysinterface::KeysInterface;
 +      use chain::keysinterface::{KeysInterface, SpendableOutputDescriptor};
        use chain::keysinterface;
+       use ln::channel::{COMMITMENT_TX_BASE_WEIGHT, COMMITMENT_TX_WEIGHT_PER_HTLC};
        use ln::channelmanager::{ChannelManager,ChannelManagerReadArgs,OnionKeys,PaymentFailReason,RAACommitmentOrder};
        use ln::channelmonitor::{ChannelMonitor, ChannelMonitorUpdateErr, CLTV_CLAIM_BUFFER, HTLC_FAIL_TIMEOUT_BLOCKS, ManyChannelMonitor};
        use ln::router::{Route, RouteHop, Router};