v4.5.4

Release of version 4.5.5:

9f61b2e build: use a version to release
0dc38fc Create README.rst
990bfe9 build: store variables using encrypted travis ci
d37be0f build: fix jacocoTestReport task name
e554a8b Automate release builds with travis
fedb92b Switch to using junit5 and gradle 5
cdc1d16 Web3j new and import small functionalliy change (#1046)