move hypothesis and khmer tests into tox

tox.ini

@@ -8,6 +8,9 @@ envlist =
   py38,
   py37,
   fix_lint,
+  hypothesis,
+  khmer,
+  khmer_master
 minversion = 3.12
 isolated_build = true
 skip_missing_interpreters = true
@@ -51,6 +54,39 @@ deps =
   pip >= 19.3.1
   psutil <= 5.6.7
 
+[testenv:hypothesis]
+commands = pytest \
+           --cov "{envsitepackagesdir}/sourmash" \
+           --cov . \
+           --cov-config "{toxinidir}/tox.ini" \
+           --junitxml {toxworkdir}/junit.{envname}.xml \
+           --run-hypothesis \
+           --hypothesis-show-statistics \
+           --hypothesis-profile ci \
+           {posargs:.}
+
+[testenv:khmer]
+deps =
+  khmer
+commands = pytest \
+           --cov "{envsitepackagesdir}/sourmash" \
+           --cov . \
+           --cov-config "{toxinidir}/tox.ini" \
+           --junitxml {toxworkdir}/junit.{envname}.xml \
+           -k test_nodegraph \
+           {posargs:.}
+
+[testenv:khmer_master]
+deps =
+  -e git+https://github.com/dib-lab/khmer.git#egg=khmer
+commands = pytest \
+           --cov "{envsitepackagesdir}/sourmash" \
+           --cov . \
+           --cov-config "{toxinidir}/tox.ini" \
+           --junitxml {toxworkdir}/junit.{envname}.xml \
+           -k test_nodegraph \
+           {posargs:.}
+
 [testenv:asv]
 description = run asv for benchmarking (compare current commit with latest)
 deps =
@@ -164,9 +200,9 @@ source = src/sourmash/
 
 [gh-actions]
 python =
-  3.7: py37, coverage, codecov
+  3.7: py37, khmer, khmer_master, coverage, codecov
   3.8: py38, docs, package_description, fix_lint, coverage, codecov
-  3.9: py39, coverage, codecov
+  3.9: py39, hypothesis, coverage, codecov
 
 [flake8]
 max-complexity = 22