[release] update version to 1.0.1

[fantazio]

Ready for release : opam install . works as expected. Upon approval of this PR, I'll publish the package on opam.

This release includes:

• https://github.com/LexiFi/dead_code_analyzer/pull/26
• https://github.com/LexiFi/dead_code_analyzer/pull/27
• https://github.com/LexiFi/dead_code_analyzer/pull/29
• https://github.com/LexiFi/dead_code_analyzer/pull/30
• https://github.com/LexiFi/dead_code_analyzer/pull/31
• https://github.com/LexiFi/dead_code_analyzer/pull/32
• https://github.com/LexiFi/dead_code_analyzer/pull/33
• https://github.com/LexiFi/dead_code_analyzer/pull/34
• https://github.com/LexiFi/dead_code_analyzer/pull/37

It improves:

• the user documentation (#26, #30, and #34)
• the support of projects built with dune (#27, #31, and #33). This was motivated by and lead to effectively using the dead_code_analyzer on Frama-C (#23)
• the test suite (#29, #31, #32, #34, and #37)