build: add travis support
build: add travis support

This adds a huge matrix of builds. The undesirable ones can be removed.

ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,pmienk/secp256k1,01BTC10/secp256k1,Bitcoin-com/BUcash,digitalbitbox/secp256k1,ChrisXin/secp256k1,Gustav-Simonsson/secp256k1,Gustav-Simonsson/secp256k1,sipa/secp256k1-zkp,digitalbitbox/secp256k1,bitcoin/secp256k1,ryancdotorg/secp256k1,voisine/secp256k1,BitcoinUnlimited/BitcoinUnlimited,martindale/secp256k1,cddjr/BitcoinUnlimited,sipa/secp256k1-zkp,vlajos/secp256k1,afk11/secp256k1,ryancdotorg/secp256k1,BWallet/secp256k1,chfast/secp256k1,01BTC10/secp256k1,marcusdiaz/BitcoinUnlimited,instagibbs/secp256k1,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,shea256/secp256k1-zkp,marcusdiaz/BitcoinUnlimited,voisine/secp256k1,krzysztofwos/BitcoinUnlimited,pmienk/secp256k1,GSongHashrate/secp256k1,voisine/secp256k1,afk11/secp256k1,afk11/secp256k1,ryancdotorg/secp256k1,voisine/secp256k1,rustyrussell/secp256k1,afk11/secp256k1,BWallet/secp256k1,apoelstra/secp256k1,sipa/secp256k1-zkp,GSongHashrate/secp256k1,rustyrussell/secp256k1,chfast/secp256k1,instagibbs/secp256k1,martindale/secp256k1-zkp,marcusdiaz/BitcoinUnlimited,libmetrocoin/secp256k1,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,libbitcoin/secp256k1,digitalbitbox/secp256k1,Justaphf/BitcoinUnlimited,BTCfork/hardfork_prototype_1_mvf-bu,vlajos/secp256k1,Gustav-Simonsson/secp256k1,GSongHashrate/secp256k1,pmienk/secp256k1,sipa/secp256k1-zkp,Bitcoin-com/BUcash,libbitcoin/secp256k1,krzysztofwos/BitcoinUnlimited,BTCfork/hardfork_prototype_1_mvf-bu,peterdettman/secp256k1,Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,sipa/secp256k1,BTCfork/hardfork_prototype_1_mvf-bu,evoskuil/secp256k1,BitcoinUnlimited/BitcoinUnlimited,peterdettman/secp256k1,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,apoelstra/secp256k1,bitcoin-core/secp256k1,ElementsProject/secp256k1-zkp,krzysztofwos/BitcoinUnlimited,jonasschnelli/secp256k1,evoskuil/secp256k1,Bitcoin-com/BUcash,sipa/secp256k1,BitcoinUnlimited/BitcoinUnlimited,Justaphf/BitcoinUnlimited,instagibbs/secp256k1,pmienk/secp256k1,martindale/secp256k1-zkp,ChrisXin/secp256k1,rustyrussell/secp256k1,randy-waterhouse/secp256k1,kleetus/secp256k1,shea256/secp256k1-zkp,libbitcoin/secp256k1,marcusdiaz/BitcoinUnlimited,kleetus/secp256k1,shea256/secp256k1-zkp,ChrisXin/secp256k1,krzysztofwos/BitcoinUnlimited,martindale/secp256k1-zkp,instagibbs/secp256k1,randy-waterhouse/secp256k1,martindale/secp256k1,bitcoin-core/secp256k1,martindale/secp256k1-zkp,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,vlajos/secp256k1,bitcoin/secp256k1,cddjr/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,BTCfork/hardfork_prototype_1_mvf-bu,ChrisXin/secp256k1,Bitcoin-com/BUcash,digitalbitbox/secp256k1,libmetrocoin/secp256k1,cddjr/BitcoinUnlimited,rustyrussell/secp256k1,01BTC10/secp256k1,GSongHashrate/secp256k1,jonasschnelli/secp256k1,pmienk/secp256k1,sipa/secp256k1,BitcoinUnlimited/BitcoinUnlimited,apoelstra/secp256k1,jonasschnelli/secp256k1,BWallet/secp256k1,Gustav-Simonsson/secp256k1,evoskuil/secp256k1,libmetrocoin/secp256k1,digitalbitbox/secp256k1,cddjr/BitcoinUnlimited,cddjr/BitcoinUnlimited,instagibbs/secp256k1,randy-waterhouse/secp256k1,sipa/secp256k1-zkp,ftrader-bitcoinunlimited/hardfork_prototype_1_mvf-bu,apoelstra/secp256k1,krzysztofwos/BitcoinUnlimited,evoskuil/secp256k1,Bitcoin-com/BUcash,shea256/secp256k1-zkp,kleetus/secp256k1,bitcoin/secp256k1,bitcoin/secp256k1,chfast/secp256k1,kleetus/secp256k1,ryancdotorg/secp256k1,marcusdiaz/BitcoinUnlimited,BWallet/secp256k1,01BTC10/secp256k1,evoskuil/secp256k1,chfast/secp256k1,randy-waterhouse/secp256k1,sipa/secp256k1,Justaphf/BitcoinUnlimited,Justaphf/BitcoinUnlimited,krzysztofwos/BitcoinUnlimited,afk11/secp256k1,voisine/secp256k1,bitcoin/secp256k1,libbitcoin/secp256k1,martindale/secp256k1,cddjr/BitcoinUnlimited,kleetus/secp256k1,vlajos/secp256k1,chfast/secp256k1,marcusdiaz/BitcoinUnlimited,martindale/secp256k1,Justaphf/BitcoinUnlimited,BTCfork/hardfork_prototype_1_mvf-bu,apoelstra/secp256k1,ElementsProject/secp256k1-zkp,Bitcoin-com/BUcash,jonasschnelli/secp256k1,libmetrocoin/secp256k1,BTCfork/hardfork_prototype_1_mvf-bu,libbitcoin/secp256k1