[all] Update to v1.0.0 (keystone-enclave#67)

Updates:
* [all] Change to follow SM v1.0 SBI (OpenSBI)
* [all] Fix compilation error for the new toolchain (RV32/RV64)
* [CI] moved from TravisCI to CircleCI
* [examples] Add return value checking for tests (`--retval` flag in the test runner)
* [src/host] Host doesn't need to initialize Untrusted Memory Resolves keystone-enclave#48 
* [all] Fix formatting
* [tests] Replace ValidMeasure test with deterministic measurement test

Issues Resolved:
keystone-enclave#48