cli: git-* commands completed with --exclude-components option

[tiborsimko]

Adds --exclude-components option to many git-* commands, allowing
to do things like:

$ reana-dev git-status -c CLIENT -c CLUSTER --base maint-0.7
--exclude-components r-a-vomsproxy,r-a-krb5

[codecov-io]

Codecov Report

Merging #443 (1fb77dc) into master (2221aa6) will decrease coverage by 0.22%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #443      +/-   ##
==========================================
- Coverage   15.06%   14.83%   -0.23%     
==========================================
  Files          16       16              
  Lines        1401     1422      +21     
==========================================
  Hits          211      211              
- Misses       1190     1211      +21     

Impacted Files	Coverage Δ
reana/reana_dev/git.py	0.00% <0.00%> (ø)

[diegodelemos]

Minor: What do you think about adding a common decorator like, @click_add_exclude_components_option, with a callback that performs this logic, like we do for tokens in R-Client?

We could even have a single option decorator for components @click_add_components_option with the possibility of taking a parameter allow_exclude_components=True so components will always be the result of select components with or without exclude components filter.

@git_commands.command(name="git-fork")
@click_add_components_option
def git_fork(components, ...):
    ...
@git_commands.command(name="git-status")
@click_add_components_option(allow_exclude_components=True)
def git_status(components, ...): 
    ...

Edited: We could create a ticket for it.

[diegodelemos]

LGTM, used a couple of commands with --exclude-components during REANA 0.7.1 release.