[modify sim cases]

make stop taosd by kill always done with continue check

Added arm64 support to travis-ci

[TD-669] add tag scripts

[TD-670]

Feature/query

Feature/pyconn: fix describe tables bugs which will cause the wrong length info of binary/nchar

Hotfix/fixbug query

1. put the definitions of variables long_shifts and short_shifts and
function shift_crc() in #ifndef _TD_ARM_, because this function and
these variables are not used/called for arm64 build in travis. Hence
warnings come up as errors.
2. Added arm64 jobs into .travis.yml by adding -DCPUTYPE=aarch64 with
cmake command.
Signed-off-by: Nodidev <odidev@puresoftware.com>

fix insert/nchar-unicode.py case.

TD-617: fix some coverity issues

[TD-669] wrong errno while drop column from normal table