feat: added option to follow symlinks

[dundee]

closes #202

[codecov]

Codecov Report

Base: 94.20% // Head: 93.85% // Decreases project coverage by -0.35% ⚠️

Coverage data is based on head (21bf5b5) compared to base (8bdce9a).
Patch coverage: 85.71% of modified lines in pull request are covered.

❗ Current head 21bf5b5 differs from pull request most recent head 0705f75. Consider uploading reports for the commit 0705f75 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #206      +/-   ##
==========================================
- Coverage   94.20%   93.85%   -0.35%     
==========================================
  Files          29       29              
  Lines        2707     2733      +26     
==========================================
+ Hits         2550     2565      +15     
- Misses        120      128       +8     
- Partials       37       40       +3     

Impacted Files	Coverage Δ
pkg/analyze/dir.go	95.67% <81.81%> (-2.18%)	⬇️
cmd/gdu/app/app.go	91.80% <100.00%> (+0.09%)	⬆️
internal/common/ui.go	100.00% <100.00%> (ø)
report/export.go	88.12% <0.00%> (-4.38%)	⬇️

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[coveralls]

Pull Request Test Coverage Report for Build 4098716972

• 27 of 30 (90.0%) changed or added relevant lines in 3 files are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.1%) to 95.469%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/analyze/dir.go	20	23	86.96%

Files with Coverage Reduction	New Missed Lines	%
pkg/analyze/dir.go	1	97.01%
report/export.go	1	94.48%

Totals
Change from base Build 4083086202:	-0.1%
Covered Lines:	2655
Relevant Lines:	2781

---

💛 - Coveralls