Implement sync-version tools

[vmax]

Fix #47

This is a tool that helps incrementing version in version file across @graknlabs repos. Currently, only incrementing patch (following semantic versioning terminology) version is supported.

Sample usage:

py_binary(
    name= "sync_version",
    srcs = ["@graknlabs_build_tools//ci:sync-version.py"],
    data= ["//:VERSION"],
    main = "ci/sync-version.py",
    args = ["$(location //:VERSION)"]
)

ghost:grakn vmax$ bazel run //:sync_version
INFO: Analyzed target //:sync_version (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
Target //:sync_version up-to-date:
  bazel-bin/sync_version
INFO: Elapsed time: 0.200s, Critical Path: 0.01s
INFO: 0 processes.
INFO: Build completed successfully, 1 total action
INFO: Build completed successfully, 1 total action
[2019-05-10 12:56:50.316]: Read version 1.5.3 from version file ./VERSION
[2019-05-10 12:56:50.316]: Writing back version 1.5.4 into version file ./VERSION

diff --git a/VERSION b/VERSION
index 8af85beb5..94fe62c27 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.3
+1.5.4

[lolski]

@haikalpribadi @vmax approved.