31926ee8cf [test] functional framework: add CScript hex() for Python 3.4 (Sjors Provoost)
74ce326831 [test] Travis: enforce Python 3.4 support in functional tests (Sjors Provoost)
Pull request description:
The minimum supported version of Python is 3.4 according to [dependencies.md](https://github.com/bitcoin/bitcoin/blob/master/doc/dependencies.md). This PR makes the Travis linter use this version in order to catch accidental use of modern syntax.
Tree-SHA512: 71b2c102be72b135a8ba049378d66875760f20a04a657102a399240c5c2b2ddbdfa7d5ab4c0c0242ecc3259e0ee8eb2273f331bc5eb824f4ae4c3cc58aea37ac