Bump scipy from 1.4.1 to 1.7.1

Bumps [scipy](https://github.com/scipy/scipy) from 1.4.1 to 1.7.1.
- [Release notes](https://github.com/scipy/scipy/releases)
- [Commits](https://github.com/scipy/scipy/compare/v1.4.1...v1.7.1)

---
updated-dependencies:
- dependency-name: scipy
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -1,6 +1,6 @@
 numpy==1.19.5
 opencv-python==4.1.2.30
-scipy==1.4.1
+scipy==1.7.1
 tensorflow==2.6.0
 colorama==0.4.4
 tqdm==4.47.0

requirements_3.6.txt

@@ -1,6 +1,6 @@
 numpy==1.19.2
 opencv-python==4.1.0.25
-scipy==1.4.1
+scipy==1.7.1
 tensorflow==2.6.0
 colorama==0.4.4
 tqdm==4.47.0

requirements_3.9.txt

@@ -1,6 +1,6 @@
 numpy==1.19.5
 opencv-contrib-python-headless==4.4.0.46
-scipy==1.6.3
+scipy==1.7.1
 tensorflow==2.6.0
 colorama==0.4.4
 tqdm==4.47.0